Taxonomy of the Polygonum douglasii (Polygonaceae) complex with a new species from Oregon M I H A I COSTEA 1 AND FRANCOIS J. TARDIF

Costea, M. (University of Guelph, Department of Plant Agriculture, Guelph, ON, N1G 2W1, Canada; email: [email protected]) and E J. Tardif (University of Guelph, Department of Plant Agriculture, Guelph, ON, N1G 2W1, Canada; e-mail: [email protected]). Taxonomy of the Polygonum douglasii (Polygonaceae) complex with a new species from Oregon. Brittonia 57: 1-27. 2005.--The taxonomy of the Polygonum douglasii complex is revised. A summary of relevant taxonomic information is provided, along with a key to the species and subspecies, plus typification, synonymy, discussion, distribution, and ecology. Morphology and micromorphology of stems, leaves, perianth, pollen, and achenes are analyzed and illustrated. Based on these data, 12 species and two subspecies are recognized. A new species, P. gabrielae, is described and illustrated from Oregon. Key words: Polygonum douglasii complex, Polygonaceae, taxonomy, morphology, micromorphology.

Polygonum L. s.str, is a c o s m o p o l i t a n genus c o m p r i s e d o f about 70 species div i d e d into t h r e e s e c t i o n s ( H a r a l d s o n , 1978). The current study examines the taxo n o m y of a group o f closely related species in section Duravia S. Watson, native to North America. One species in this group, P. douglasii Greene, has been interpreted (e.g., H i c k m a n , 1993; Kartesz, 1998) as a c o m p l e x species c o m p r i s i n g seven partially sympatric subspecies: subsp, douglasii, subsp, johnstonii (Munz.) J. C. H i c k m a n , subsp, spergulariiforme (Meisn. ex Small) J. C. Hickman, subsp. majus (Meisn.) J. C. H i c k m a n , subsp, nuttallii (Small) J. C. H i c k m a n , subsp, austiniae (Greene) Murray, and subsp, engelmannii (Greene) Kartesz & Gandhi. Several other species, however, share the s a m e close t a x o n o m i c affinities and geographic distribution with P. douglasii: P. tenue Michx., P. minimum S. Watson, P. cascadense W. H. Baker, and P. utahense Brenckle & Cottam. Should all these species J Corresponding author

be c o m b i n e d in a broadly defined P. douglasii? Furthermore, during the preparation of Polygonum s. str. for Flora o f North America, collections within this range o f variation were found that m a t c h none o f these taxa. Therefore, the m a i n purpose o f this study is to analyze the variation patt e r n s and r e l a t i o n s h i p s b e t w e e n t h e s e closely related taxa. M i c r o m o r p h o l o g y o f perianth lobes and leaves, as well as the m o r p h o l o g y o f pollen, have p r o v e d to be useful for the infrageneric classification o f the t r i b e P o l y g o n e a e ( H e d b e r g , 1946; R o n s e Decraene & Akeroyd, 1988; H o n g et al., 1998; H o n g & Oh, 1999). Additionally, the surface of achenes was important to distinguish b e t w e e n species o f the section Polygonum (Wolf & McNeill, 1986). Another a i m o f this study is to test the taxonomic usefulness o f such m i c r o m o r p h o logical characters for this group o f taxa. Methods MO R P H O LO G Y

Descriptions and distribution of taxa are based on specimens f r o m A, ALTA, CAS,

Brittonia, 57(1), 2005, pp. 1-27. 9 2005, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.

ISSUED: 31 March 2005

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DAO, DC, DS, G H , F, JEPS, LL, MT, M T M G , NY, O A C , POM, QFA, RSA, SASK, TEX, U B C , UC, US, and U S A S . Mature plants with leaves, flowers, and achenes are necessary for accurate determinations. Plants parasitized by homopteran insects are atypical. Their internodes are shortened, c y m e s have numerous flowers, and inflorescences are denser; flowers are brownish, sterile, and pedicels m a y be erect even in taxa in which they are normally reflexed. Papillae are easily observed on young stems or toward apices of mature stems and branches, at magnifications higher than 5 0 • Measurements of leaves and ocreae were m a d e at the middle of the main stem. T h e state c h a r a c t e r s , " f l o w e r s closed," "flowers s e m i o p e n , " and "flowers w i d e - o p e n " were noted on herbarium specimens. Description of perianth refers to the fruiting perianth, which was measured f r o m the joint with the pedicel. M o r p h o l o g y of pedicels was noted in fruit. Measurements of dry anthers were obtained f r o m S E M pictures (see below). MICROMORPHOLOGY

Samples ( A p p e n d i x l) were collected f r o m typical h e r b a r i u m specimens within the holdings o f C A S , DS, GH, JEPS, NY, RSA, UC, and U S A S . Samples were coated with 30 n m gold using an E m i t e c h K 5 5 0 • Sputter Coater and e x a m i n e d with a Hitachi S-570 at 15 KV. M i c r o m o r p h o l ogy of the following organs or plant parts was examined: mature stems and leaves, fruiting perianth, and pollen. Surface pattern o f perianth was studied on the borders o f the outer perianth lobes. Standard term i n o l o g y for cell types and surface sculpturing patterns follows Ronse D e c r a e n e a n d A k e r o y d ( 1 9 8 8 ) , B a r t h l o t t et al. (1998), and H o n g et al. (1998). Pollen term i n o l o g y follows H o e n (1999). Description of achene m o r p h o l o g y and m i c r o m o r p h o l o g y follows the t e r m i n o l o g y developed by W o l f and McNeill (1986) and Ronse D e c r a e n e et al. (2000).

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es (Fig. 1C, D, F). Epidermis cells are rectangular or elongated, with epicuticular wax consisting o f longitudinal rodlets (Fig. 1C). Stomata are frequent, mostly anisocytic (rarely a few may be anomocytic). Presence of papillae is a distinctive feature o b s e r v e d in m a n y taxa. Papillae m a y be distributed on the stem angles or on the ribs and between these (Fig. 1C, D, F). They may be patent or more or less retrorse. Papillae shape varies f r o m --- spherical, 7 - 1 8 btm, located at the same level with the epidermis cells (Fig. 1A), conical with a swollen base, 4 0 - 6 0 ~ m (Fig. 1B), to conical-elongated or cylindrical, 1 0 0 - 2 0 0 ~ m long, approaching hairs (Fig. 1C, D). Epicuticular wax o f papillae is organized as parallel rodlets (Fig. 1B). LEAVES AND OCREAE

Leaves are obviously jointed to ocreae, which m a y be short, funnelform 2 - 5 m m , or longer, 5 - 1 2 m m , with the free part becoming lacerate or disintegrating into a few fibers. Petioles are very short or absent. Blades are variably shaped, linear to round, and 1-veined. L e a f blade epidermis cells are irregularly shaped or elongated, with m o r e or less undulate anticlinal walls. Stomata are usually present on both epidermis, and they are mostly anisocytic (rarely a few m a y be anomocytic). Margins of the leaves are often revolute (Fig. 2A), or sometimes plane. In P. utahense, the revolute margins join together on the abaxial side of the blade (Fig. 2B). Conical or conical-elongate papillae, similar to those present on the stems, m a y occur on the ocreae and lamina margins in m a n y taxa (Fig. 1F, 2C, D). Presence of papillae on the rest of lamina has been d o c u m e n t e d only in P. utahense (Fig. 2B, F) and sometimes in P. spergulariiforme (Fig. 2E). Epicuticular wax is organized as longitudinal rodlets or threads (Fig. 2E); only in P. utahense do the rodlets f o r m a reticulate pattern (Fig. 2F). PERIANTH

Results STEMS

Stems are 4-angled, with smooth (Fig. 1A) or minutely and irregularly ribbed fac-

The perianth consists of two outer tepals, one intermediate (transitional), and two inner tepals fused for 8 - 4 0 % of their length. The outer and the intermediate perianth

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FIG. 1. Micromorphology of stems. A. Polygonum tenue, arrows indicate papillae (scale bar = 100 p,m). B. P, minimum (scale bar = 75 ~zm). C. P. spergulariiforme (scale bar = 100 p~m), D. P. sawatchense subsp. oblivium (scale bar = 25 l,zm), E. P. sawatchense subsp, sawatchense (scale bar 50 = mm). F. P. nuttallii (scale bar = 50 mm).

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"27/;Y/W,' i ~.~+ c,:;,(.)~ <.*,-t~ ,-,~;.:~@, A,-F$/."KI7 J;---.s.;%~~/~

H ~,' '?SPt -..':~e',.', ~>,~'<~%e'.O/w,J,i l f ~

r :.

yl

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. .,,...>.<,L,

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r~." ' -

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.,.~,' ~ : 1 ; ; 6 . / 2 ] r

FIG. 2. M i c r o m o r p h o l o g y o f leaves. A - D . Margin o f the leaf. A. Polygonum sawatchense subsp, sawatchense (scale bar = 0.3 ram). B. P. utahense (scale bar = 0.3 ram). C. P. sawatchense subsp, oblivium (scale bar = 100 ixm). D. P. spergulariiforme (scale bar = 100 ixm). E, F. papillae on the leaf blade: E. P. spergulariiforme. F. P. utahense (scale bars = 30 txm).

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C O S T E A & TARDIF: P O L Y G O N U M DOUGLASII C O M P L E X

lobes are oblong-elliptic to oblong-obovate, often cucullate and overlapping, naviculate along their entire length or only in the upper 1/4 (Fig. 3). Vasculature of tepals consists of a single vein, which may be branched or not. EPICUTICULAR WAX PATTERN OF PERIANTH LOBES

Epidermis cells are irregularly shaped, elongated or rectangular (Figs. 4, 5). Stomata are usually present. The anticlinal walls are usually sinuate or sometimes straight or weakly undulate (Figs. 4, 5). Epicuticular wax sculpture pattern is variable and complex: Type 1. Epidermis cells with the periclinal walls more or less flat. Sculpture pattern is homogenous on the same cell. Wax rodlets may be arranged in a dense reticulate, intertwined pattern (Figs. 4C, 5E, F) or they may be more or less transversally oriented (Fig. 4A, B). Type 2. Epidermis cells with the periclinal walls evidently convex. Sculpture pattern is heterogeneous on the same cell: wax rodlets are ___ parallel among themselves and perpendicular to the long axis of cells on the lateral inclined faces and arranged in a dense reticulate and intertwined pattern on the more or less fiat top of the periclinal walls (Fig. 4 D - E 5 A D).

5

the mesocolpia and poles, and microretic u l a t e - f o v e o l a t e or s o m e t i m e s f o v e o l a t e with microspinules around ectoapertures (Fig. 6). Two distinct types can be recognized based the size of the pollen grains, the reticulum sculpturing at the middle part of the mesocolpium and the sculpturing o f ectoapertures: Type A. Pollen grains 2 0 - 2 6 ixm long; mesocolpium is microreticulate with 1-7 rows of lumina, 0.5-1(-1.1) Ixm in diameter, clearly differentiated or undifferentiated from the ectoapertures, which are microreticulate to tectate perforate, foveolate-punctate, sometimes with microspinules. 9 Subtype A l . - - M e s o c o l p i u m is microreticulate and not clearly differentiated from the ectoapertures. Mesocolpium microreticulum with 4 - 7 rows of lumina, 0.5-0.9 txm in diameter (Fig. 6A-C). 9 Subtype A 2 . - - M e s o c o l p i u m is reticulate, clearly differentiated from ectoapertures. Mesocolpium reticulum with 15 rows of lumina, 0.9-1.1 Ixm in diameter (Fig. 6D, E). Type B. Pollen grains 28-33 ixm; mesocolpium is reticulate with 1-2 rows o f lumina, 1.5-4 txm in diameter; mesocolpium is sharply differentiated from the ectoapertures, which are tectate imperforate, rarely punctate, with a few puncta (Fig. 6F-H).

STAMENS

ACHENES

Stamens are most commonly eight, arranged in two " w h o r l s . " The outer whorl consists of five stamens and the inner o f three stamens. S t a m e n s in the o u t e r " w h o r l " may be reduced, sometimes entirely (e.g., P. sawatchense subsp, sawatchense). The base o f the inner stamens is thickened and associated with a nectarial tissue. Anthers are short, 100-550 Ixm, pink to purple, rarely whitish.

A c h e n e s are black, t r i g o n o u s , ovate, ovate-lanceolate, elliptic, and enclosed in the perianth or exserted at maturity (Fig. 7). Faces are concave and subequal; one face is slightly broader than the other two (Fig. 7). The exocarp is usually lustrous and smooth, or sometimes it may be striate-tubercled, especially near the edges and apex o f achenes (Fig. 7C, F). Tubercles may be arranged in longitudinal rows, more or less following the anticlinal walls (Fig. 7D).

POLLEN

The pollen belongs to the "Duravia type" described by Hedberg (1946). It is prolate, usually tricolporate with the exine semitectate-reticulate or microreticulate at

Taxonomy H i c k m a n (1984) i n c l u d e d within P. douglasii five other species that share a significant area of sympatry: P. sawatchense

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FIC. 3. Morphology of flowers. A. Polygonum douglasii. B. P. sawatchense subsp, oblivium. C. P. nuttallii. D. and E. P. gabrielae. F. P. sawatchense subsp, sawatchense. G. P. utahense. H. P. cascadense. I. P. engelmannii. J. P. austiniae. Scale bars = 1 ram.

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~z- > ~ .

7

~_~',;-~~q,...,~-_-~,"

FIG. 4. Epicuticular wax sculpture pattern of perianth lobes. A. Polygonum tenue. B. P. douglasii. C. P. sawatchense subsp, sawatchense. D~ P. sawatchense subsp, oblivium. E. P. spergulariiforme. F. P. majus. Scale bars = 20 ~m.

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r

FIG. 5. Epicuticular w a x sculpture pattern of perianth lobes. A. Polygonum austiniae. B. P. utahense. C. P. engelmannii. D. P. gabrielae. E. P. minimum. F. P. nuttallii. Scale bars = 20 ixm.

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FIC. 6. Morphology o f pollen. A. P. douglasii. B. P. tenue. C. P. sawatchense subsp, sawatchense. D. P. sawatchense subsp, oblivium. E. P. minimum (scale bars = 5 ixm). F. P. nuttallii (scale bar = 4 txm). G. P. gabrielae. H. P. majus (scale bar = 4 txm).

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Fro. 7. Morphology and micromorphology of achenes. A. Polygonum sawatchense subsp, sawatchense. B. P. sawatchense subsp, oblivium. C. P. tenue. D. P. douglasii. E. P. majus. F. P. spergulariiforme. G. P. austiniae. H. P. engelmannii. I. P. gabrielae. J. P. utahense. Scale bar = 1 m m for all figures except Figure 7D where scale bar is 100 p~m.

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Small, P. spergulariiforme M e i s n . ex Small, P. majus Meisn., P. nuttallii Small, and P. austiniae Greene. He justified these new combinations by the intermediate patterns of variation between some of the taxa. A sixth species, P. engelmannii Greene was put in s y n o n y m y under P. douglasii based on a previous observation that the two taxa are closely related (Hitchcock, 1964) and because "the distinction of these two taxa is not always clear" (Kartesz & Gandhi, 1990). The majority of collections annotated as " i n t e r m e d i a t e s " by H i c k m a n (in CAS, DS, JEPS, RSA, and UC) are either between "P. douglasii subsp, douglasii and subsp, johnstonii" (P. douglasii and P. sawatchense subsp, sawatchense, respectively) or between P. douglasii and P. spergulariiforme. Most o f these " i n t e r m e d i a t e s " are, in our opinion, within the range of variation of each taxon, which has been poorly understood. In the first case, plants regarded b y H i c k m a n as i n t e r m e d i a t e s b e t w e e n "subsp. douglasii and subsp, johnstonii" are either P. douglasii or P. sawatchense subsp, sawatchense ( C o s t e a & Tardif, 2003a). In the second case, most o f the plants considered by H i c k m a n intermediates between P. douglasii and P. spergulariiforme belong, in our opinion, to P. majus. In most of the situations encountered, plants can be assigned to each species using qualitative or quantitative characters. H y bridization m a y have played a role in the evolution of this group of species, but the relatively low levels of introgression observed do not warrant their combination in a single species. The close relationship between these taxa does not justify a cumbersome species concept of P. douglasii, to which should also be added following the same criterion even m o r e species: P. minimum, P. cascadense, and P. utahense, as well as a previously undescribed species, P. gabrielae. This is not the same situation within the P. aviculare L. complex, where taxa are linked by a continuum transition of variation patterns, which makes their recognition at species rank unrealistic (Costea & Tardif, 2003b). Consequently, a species

11

concept closer to that o f Small (1895) and Hitchcock (1964) is followed here (see also the discussions under each species). This group of species is probably m o n o phyletic and m a y be worth recognizing as a subsection o f the section Duravia (emended by Hedberg, 1946). H i c k m a n (1984) elevated Duravia to the subgenus rank and separated f r o m it a new section, Monticola, in which he included the species of the P. douglasii and P. polygaloides complexes. According to this classification, section Duravia incorporates species f r o m lowland and foothill locations, with leaves not obviously jointed to ocreae, linear, 3-nerved (rarely 1-nerved), mucronate apex and styles separate, hardened, and persistent at least at the base. In contrast, Monticola includes species f r o m montane areas, with leaves obviously jointed to ocreae, apex not mueronate, at least lowest leaves lanceolate to round and styles, that are fused at base and neither hardened nor persistent (Hickman, 1984). However, we found a considerable overlap between Duravia and Monticola in t h e s e c h a r a c t e r s . A d d i t i o n a l l y , some species f r o m Duravia cannot be classified in any of the two sections (e.g., P. shastense Brewer ex A. Gray and P. paronychia Cham. & Schlecht.). Therefore, in this study, section Duravia is interpreted to include section Monticola. The latter section, circumscribed here to include only the species of P. douglasii complex, m a y be accepted after further study as a subsection o f Duravia. S o m e authors (Ronse Decraene & Akeroyd, 1988; Ronse Decraene et al., 2000) suggested that even section Duravia is artificial because o f the partial overlap in floral and fruit characters between some o f its species and the section Polygonum. Although section Duravia is heterogeneous and shares s o m e features with section Polygonum (Ronse Decraene & Akeroyd, 1988; Ronse Decraene et al., 2000), the morphology of stems, color of anthers, venation pattern, structure of petioles (Haraldson, 1978), and m o r p h o l o g y o f p o l l e n (Hedberg, 1946) clearly separates the two sections.

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Key to the Polygonum douglasii complex 1. 2. 2.

Pedicels patent or erect. Leaves with one pleat on each side of the midvein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. tenue Leaves not pleated. 3. Ocreae 1 - 4 m m long, funnelform; perianth 1.8-2.5 m m long; achenes 1.8-2.3 m m long. 4. Plants 1.5-3.5 c m tall; leaves and bracts uniformly papillose, cylindrical due to revolute margins that join together on the abaxial face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. u t a h e n s e 4. Plants 3 - 5 0 c m tall; leaves and bracts glabrous or papillose only on the margins; leaves plane or with narrow revolute margins, which are never joined together on the abaxial face. 5. Plants glabrous; flowers wide-open .................................................................. P. c a s c a d e n s e 5. Plants papillose-scaberulous at least on the ocreae; flowers closed or semiopen. 6. Leaves elliptic, obovate to subround, pure green adaxially, margins plane or narrowly revolute, irregularly thickened or denticulate-papillose; anthers 120-165 Izm long ...............................................................................................

P. m i n i m u m

6.

1.

Leaves linear to narrow elliptic, _+ glaucescent adaxially, margins revolute, smooth; anthers 2 5 0 - 3 2 5 )*m long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .n u t t a l l i i 3. Ocreae 4 - 1 2 m m long, not funnelform; perianth 3 - 5 m m long; achenes 2.5-5 m m long. 7. Inflorescence dense, c y m e s crowded and overlapping at stem and branch apices; anthers 4 0 0 - 5 5 0 btm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. spergulariiforme 7. Inflorescence open, c y m e s regularly spaced along stem and branches; anthers 1 3 0 - 2 0 0 I~m long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. sawatchense 8. Stems and ocreae glabrous; leaf blades linear to linear-lanceolate, smooth on the margins. ........................................................ P . s a w a t c h e n s e subsp, s a w a t c h e n s e 8. Stems and ocreae scaberulous-papillose; leaf blades elliptic or elliptic-lanceolate, denticulate-papillose on the margins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . s a w a t c h e n s e subsp, o b l i v i u m Pedicels reflexed. 9. Ocreae 6 - 1 2 m m long; flowers and achenes 3 - 5 m m long. 10. Flowers wide-open or semiopen; pedicels 0.5-1 m m long; perianth tube 9 - 1 7 % of the perianth length; anthers 4 0 0 - 5 5 0 p.m long ......................................................... P. m a j u s 10. Flowers mostly closed; pedicels 2 - 6 m m long; perianth tube 20 28% o f the perianlh length; anthers 1 2 5 - 1 5 0 ~ m long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. d o u g l a s i i 9. Ocreae 3 - 5 m m long; flowers and achenes 2 - 3 m m long. 11. Inflorescence dense, c y m e s overlapping at stem and branch apices; flowers wide-open, with the tube I 0 - 1 5 % o f the perianth length; anthers 3 2 5 - 3 8 0 bLm Iong ................... P. g a b r i e t a e 11. Inflorescence elongated, spike-like, c y m e s spaced along stem and branches; flowers closed, with the tube 2 5 - 3 3 % o f the perianth length; anthers 1 0 0 - 1 6 0 ttm long. 12. Tip o f mature achene exserted from perianth; lower leaves linear-oblanceolate with smooth margins .................................................................... P. engelmannii 12. Tip of mature fruit enclosed in perianth; lower leaves broadly elliptic to ovate, with margins minutely denticulate-papillose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. a u s t i n i a e

1. POLYGONUM TENUE M i c h x . , F1. Bor. Amer. 1: 238. 1803. TYPE: C A N A D A . " H e r b i e r de l ' A m d r i q u e septentrionale. In Canada, at M o n a Caesarea ad Snake Bill," Michaux s . n . (LECTOTYPE, here designated: P, specimens on left side of sheet). t e n u e var. p r o t r u s u m Fernald, Rhodora 44: 393. 1942. TYPE: United States. Virginia. Southhampton Co.: Blackwater River, SE of Ivor, 16 Oct 1941, Fernald & L o n g 13937 (HOLOTYPE: GH; isotypes: NY, US).

Polygonum

Annual herbs. Stems 5 - 5 0 c m long, 4 angled, green or brownish, erect, simple or branched, with a few to m a n y branches, upper edges glabrous, _+ winged or denticulate-papillose; papillae on the edges (when present) conical, 8 0 - 1 2 0 ),m, papillae on

the stem faces spherical, 7 - 1 8 ~m, located at the same level with the epidermis cells (Fig. 1A). Leaves: basal leaves caducous or persistent at flowering; upper leaves reduced to scale-like bracts upward; ocreae 6 - 1 5 m m , glabrous, free part soon disintegrating into a few brown fibers; blades narr o w l y lanceolate to linear, with 2 deep pleats parallel to the midvein, 2 5 - 4 0 • 18 m m , margins usually plane, denticulatepapillose, apex mucronate or cuspidate. Papillae on leaf margins conic-elongated or cylindrical, 110-200 ~m. Inflorescences terminal, spike-like, slender and elongated; c y m e s 1 or 2 ( 3 ) f l o w e r e d , widely spaced along stem and branches; bracts shorter to equaling the flowers they subtend. Flowers closed; pedicels erect, 1-1.5 m m ; perianth

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2.5-4.2 ram, the tube 15-22% of the perianth length, perianth lobes petaloid or sepaloid, cucullate, naviculate, overlapping, green (often brownish when dried), with pink or white borders; perianth lobe cells rectangular, 3 3 - 4 5 • 18-22 txm, with the anticlinal walls straight; epicuticular wax pattern of type 1, with a transversal pattern o f rodlets (Fig. 4A). Stamens 8, with pink or purple anthers, 125-150 ~ m long. Pollen o f s u b t y p e A1, 2 1 - 2 4 ~ m (Fig. 6B). Achenes elliptic to oblong, 2 . 3 - 4 m m , included in the perianth or slightly exserted at maturity, smooth or minutely striate-tubercled near the edges and apex (Fig. 7C). 2n = 20 (L6ve & L r v e , 1956). L6ve and L r v e (1956) reported that they obtained fertile hybrids f r o m crosses between P. tenue and P. douglasii. This study was criticized and its results disregarded because authors did not cite any vouchers and because some c h r o m o s o m e counts were doubtful (e.g., Mertens & Raven, 1965; Wolf & McNeill, 1987). However, P. t e n u e is hardly mistakable with any other P o l y g o n u m species because of its peculiar leaf morphology. This is the only species of the section D u r a v i a that has evolved in central and eastern North America. Its geographical distribution (see below) extends westwards to W y o m i n g and overlaps in part with that of P. d o u g l a s i i and P. s a w a t c h e n s e subsp, s a w a t c h e n s e . Morphologically and micromorphologically the three taxa are similar. T h e y have the A l - s u b t y p e o f pollen grains and perianth lobes with epicuticular wax organized as transversally oriented rodlets. All evidence indicates that P. tenue, P. s a w a t c h e n s e , and P. d o u g l a s i i m a y connect section D u r a v i a to section P o lygonum.

Two geographically distinct collections o f P. tenue are m o u n t e d on the type sheet. The left group o f specimens are from Canada. Because they are mature and more numerous, they are here designated as a lectotype. The collections from the right are f r o m the United States, "stam. 7, stili 3, in pratensibus Illinoesimum." They are immature but easily recognizable by the morphology of the leaves. Distribution a n d e c o l o g y . - - C a n a d a (southern Ontario) and the United States (Ala-

13

bama, Arkansas, Connecticut, Delaware, District of Columbia, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, southern Maine, Maryland, Massachusetts, southern Michigan, southern Minnesota, Missouri, Nebraska, N e w Hampshire, N e w Jersey, N e w York, western North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Tennessee, eastern Texas, Vermont, Virginia, West Virginia, southern Wisconsin, and Wyoming). It grows on dry, sandy, acid soils, in exposed locations. P h e n o l o g y . - - F l o w e r i n g June-October. 2. POLYGONUM DOUGLASIIGreene, Bull. Calif, Acad. Sci. 1: 125. 1885. TYPE: U N I T E D S T A T E S . C a l i f o r n i a . Tulare Co.: Coyote Creek, 30 Jul 1904, Culberson 4391 (NEOTYPE designated by H i c k m a n 1984: DS; ISONEOTYPE: NDG). Polygonum tenue var. latifolium Engelm. in A. Gray,

Proc. Acad. Nat. Sci. Philadelphia 1863: 75. 1863. Polygonum douglasii var. montanum Small, Mem. Dept. Bot. Columbia Coll. 1: 118. 1895. Polygonum douglasii var. latifolium (Engelm. ex A. Gray) Greene, Bull. Calif. Acad. Sci. 1: 125. 1885. Polygonum montanum (Small) Greene, P1. Baker. 3: 13. 1901. TYPE:not designated. Polygonurn emaciatum A. Nelson, Bot. Gaz. 54: 138. 1912. TYPE: UNITED STATES. Idaho. Gem Co.: "doby" lava slopes, near Sweet, 14 Aug 1911, MacBride 1692 (LECTOTYPE,here designated: RM; mOLECTOTYPES:GH, US, WS-n.v. Annual herbs. Stems 5 - 8 0 c m long, 4angled, green, erect to ascendent, simple to freely branched f r o m below the middle, glabrous with smooth faces, or angles with sparse papillae; papillae conical, 4 0 - 6 0 Ixm long. Leaves: basal leaves usually caducous or persistent at flowering, upper leaves abruptly reduced to scale-like bracts; ocreae 6 - 1 2 m m , glabrous or sparsely scaberulouspapillose, with the free part hyaline, lacerate; leaf blades linear, narrow-oblong, oblanceolate to oblong, 15-55 • 2 - 8 ( - 1 2 ) m m , margins smooth or denticulate-papillose; apex acute or mucronate. Papillae on ocreae and leaf margins are similar to those on the stems, or they m a y be conic-cylindrical, 6 0 - 8 5 Ixm long. Inflorescences terminal, elongated and spike-like; c y m e s 2 4-flowered, regularly spaced along the stem and branches; bracts equaling or s o m e w h a t longer than the flowers. Flowers closed;

14

BRITTONIA

pedicels reflexed, 2 - 6 ram; perianth 3-4.5 ram, the tube 2 0 - 2 8 % of the perianth length, perianth lobes petaloid or sepaloid, cucullate, naviculate, overlapping, tannish to green, margins white or pink, midveins usually branched, rarely unbranched (Fig. 3A); perianth lobe cells rectangular 3 0 - 6 0 • 9 - 1 5 txm with anticlinal walls straight or weekly sinuate; epicuticular wax pattern belongs to type 1 and has transversally reticulate rodlets (Fig. 4B). Stamens 6-8; anthers pink to purple, 125-150 Ixm long. Pollen of subtype A1, 2 2 - 2 4 txm (Fig. 6A). Achenes elliptic, oblong to ovate, 3 - 4 ( 4.5) mm, enclosed in the perianth at maturity, smooth or tubercled. Greene (1885) described P. douglasii var. latifolium with " s a w - t o o t h e d , " o b l o n g blades, and oblong achenes, as opposed to var. douglasii having linear-lanceolate to lanceolate or oblanceolate, glabrous leaves, and ovate achenes. This variety has been accepted by Hitchcock (1964), but the authors abandoned the leaf margin and achene shape characters. Indeed, we have encountered P. douglasii plants with narrow-lanceolate leaves having denticulate-papillose margins, as well as plants with glabrous oblong leaves. Achene shape also varies from elliptic to oblong or ovate, with no relation to the blade width. Although plants with wide leaves tend to occur more frequently at higher altitudes, leaf shape varies continuously, and the two varieties cannot be sati s f a c t o r i l y separated. Plants with b r o a d leaves bring P. douglasii close to P. austiniae and to P. sawatchense subsp, oblivium. In fact, Hickman (in herb.) regarded such plants as intermediates between P. douglasii " s u b s p . johnstonii (P. sawatchense subsp, sawatchense) and subsp, douglasii." However, P. douglasii is readily distinguished from P. austiniae by its bigger flowers and achenes. From P. sawatchense subsp, oblivium it differs by the glabrous stems, reflexed achenes, and the pollen of subtype A1. From both taxa, it is distinguished by the epicuticular wax sculpture o f perianth lobes with transversally reticulate rodlets. Distribution and ecology.--Canada (Alberta, British C o l u m b i a , S a s k a t c h e w a n , Manitoba, Ontario, and Qurbec) and the

[VOL. 57

United States (Arizona, California, Colorado, Idaho, Maine, Maryland, Michigan, Minnesota, Montana, Nebraska, New York, Nevada, New Hampshire, New Mexico, New York, North Dakota?, Oregon, South Dakota, Utah, Vermont, Virginia, Washington, and Wyoming). It grows in dry, montane and lowland areas, sometimes disturbed places, at elevations ranging from 500 to 3000 m. Phenology.--Flowering June-October. 3. POLYGONUM SAWATCHENSE Small, Bull. Torrey Bot. Club 20: 213, pl. 156. 1893. TYPE: U N I T E D S T A T E S (State and County not given). Yellowstone Park, 1885, Tweedy s.n. (NEOTYPE designated by Costea & Tardif, 2003a: US). Annual herbs. Stems 5 - 5 0 cm long, 4angled, g r e e n to b r o w n i s h , simple or branched from base, glabrous or scaberulous-papillose. Leaves: basal leaves persistent or caducous at flowering, upper leaves abruptly reduced to scale-like bracts, or much longer than the flowers they subtend; ocreae 4 - 1 2 mm, glabrous or scaberulous papillose, free part lacerate or disintegrating into a few fibers; blades linear, narrow-oblong to oblanceolate or oblong elliptic to elliptic, 15-45 • 2 - 8 ( - 1 2 ) ram; margins smooth or denticulate-papillose; apex acute or mucronate. Inflorescences axillary or terminal, long, open spike-like thyrses; cymes 2 - 4 ( - 6 ) - f l o w e r e d widely spaced along the branches; bracts equaling to much longer than the flowers they subtend. Flowers closed or wide-open; pedicels erect, 1-4 ram; perianth 2.8-3.5 mm; the tube 2 0 40% of the perianth length, perianth lobes petaloid or sepaloid, cucullate, naviculate, overlapping, greenish or reddish, with white or pink borders; midveins unbranched or with a few branches at base. Stamens 3-8; anthers pink to purple, rarely whitish, 1 3 0 200 ~m. Pollen of type A. Achenes elliptic, 2.5-3 ram, enclosed in perianth at maturity, smooth. The species is variable and two subspecies have been recognized (Costea & Tardif, 2003a). Although the two subspecies are distinct, intermediates may occur in the areas of sympatry.

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POLYGONUM SAWATCHENSE SAWATCHENSE

Small subsp.

Polygonum douglasii Greene var. johnstonii Munz, Man. So. Calif. Bot. 131: 597. 1935. Polygonum douglasii subsp, johnstonii (Munz) J. C. Hickman, Madrofio 31: 250. 1984. TYPE: UNITED STATES. California. San Bernardino Co.: San Bernardino Mts., Fish Creek, 2320 m, Munz & Johnston 8506 (HOLOTYPE"RSA). Polygonum exile Eastw., Proc. Calif. Acad. Ser. 3, Bot. 2: 286. 1902. TYPE: UNITED STATES. California (County not given). Kings River Canyon, 4 Jul 1899, Eastwood s.n. (HOLOTYPE: CAS). Polygonum triandrous Coolidge, Madrofio 20: 266. 1970. TYPE: UNITED STATES. Idaho. Blaine Co.: Hyndman Peak Trail, 13 Aug 1953, Baker 11005 (HOLOTYPE: ID; ISOTYPES: OSC, UC, W S n.v., WTU-n.v.).

Stems 4 - 5 0 cm long, green to brownish, usually branched from base, glabrous, with smooth faces (Fig. 1E) and sometimes narrow winged angles. Leaves caducous or persistent at flowering, upper leaves abruptly reduced to scale-like bracts or much longer than the flowers they subtend; ocreae glabrous; blades linear, narrow-oblong to oblanceolate, 15-45 x 2 - 8 ( - 1 2 ) m m ; margins usually revolute, smooth (Fig. 2A). Inflorescences axillary or long, open spikelike thyrses; c y m e s 2 - 4 ( - 6 ) - f l o w e r e d , widely spaced along branches; bracts equaling or much longer than the flowers. Flowers mostly closed; pedicels erect, 1-4 ram, perianth (2.8-)3-3.5 mm; the tube 2 5 - 4 0 % o f the perianth length (Fig. 3F), perianth lobes greenish or reddish with white or pink borders; midveins unbranched or with a few branches at base; perianth lobe cells rectangular, 3 0 - 5 0 X 10-17 txm, with anticlinal walls straight or weekly sinuate; epicuticular wax pattern of type 1, with reticulate rodlets (Fig. 4C), which may sometimes be m o s t l y t r a n s v e r s a l l y o r i e n t e d . Stamens 3-8; anthers pink to purple, 1 3 0 160 txm, Pollen of subtype A1, rarely A2, 21.2-26 txm long (Fig. 6C). Achenes 2 . 5 3 ram. elliptic (Fig. 7A). Distribution and ecology.--Canada (Alberta, Saskatchewan), the United States (Arizona, C a l i f o r n i a , C o l o r a d o , Idaho, Montana, Nevada, New Mexico, North Dakota, South Dakota, Utah, Washington, Wyoming), and Mexico (Baja California). It grows in dry meadows, pastures, sagebrush

15

and forests on sandy, gravelly, or rocky substrates. Phenology.--Flowering June-August. subsp. OBLIVIUM, Costea & Tardif, Sida 20: 1637. 2003. TYPE: U N I T E D STATES. California. Sisk i y o u Co.: S a l m o n M o u n t a i n s , H i g h Lake Basins in the vicinity of English Peak, Marble Mountain Wilderness Area, gully near m e a d o w SE of Tom Taylor Cabin, 2040 m, 13 Aug 1967, Oettinger 260 (HOLOTYPE; RSA).

POLYGONUM SAWATCHENSE

Polygonum douglasii subsp, johnstonii auct.

Stems 5 - 1 5 ( - 2 5 ) cm long, green, simple or with a few branches from base, scaberulous-papillose on and between ribs; papillae white, patent, dense, conic-elongated to cylindrical, 9 0 - 1 5 0 Ixm (Fig. 1D). Leaves usually persistent at flowering and gradually decreasing in size upwards; ocreae 4 10 mm, scaberulous-papillose, with the free part lacerate or disintegrating into a few fibers; blades elliptic to oblong-elliptic, 8 20(-25) • 5 - 1 0 mm; margins plane, denticulate-papillose (Fig. 2C). Papillae on ocreae and leaf margins are similar to those present on the stems (Figs. 1D, 2C). Inflorescences mostly axillary, or if a terminal spike-like thyrse is present, than it is shorter than 5 cm; cymes 1 or 2(3)-flowered; bracts leaf-like, much longer than the flowers. Flowers; at least some of them wide-open; pedicels erect, 1-3 mm; perianth 3 - 4 ram, tube 2 0 - 3 0 % of the perianth length, perianth lobes cucullate, naviculate and overlapping (Fig. 3B), greenish white or greenish yellow (sometimes flushed with purple), with white borders; midveins greenish or brown usually branched at base; perianth lobe cells elongated, 4 5 - 6 5 • 5-8 ixm, with the anticlinal walls strongly sinuate; epicuticular wax pattern o f type 2, with a narrow longitudinal pattern o f reticulate rodlets at the top of cells (Fig. 4D). Anthers pink to purple, which rarely may be whitish, 1 3 0 200 txm. Pollen of subtype A2, 26-29 ixm (Fig. 6D). Achenes 2.6-3.3 mm, elliptic (Fig. 7B). This taxon has erroneously been referred to as P. douglasii subsp, johnstonii. The latter name is based on the epithet of the het-

16

BRITTONIA

erotypic P. douglasii var. johnstonii that has caducous oblong-lanceolate leaves and the entire plant is glabrous and more or less glaucous. However, such plants are within the range of variation o f P. sawatchense subsp, s a w a t c h e n s e ( C o s t e a & Tardif, 2003a). The stems of P. sawatchense subsp. o b l i v i u m are s c a b e r u l o u s papillose, the leaves are oblong-elliptic to elliptic, papillose denticulate on the margins, the flowers, at least some of them, are open, and the pollen belongs to the subtype A2. Polygoh u m sawatchense subsp, sawatchense is glabrous, the leaves are linear to oblanceolate, flowers are normally closed, and the pollen belongs to subtype A1 or A2. The micromorphology of perianth surface o f the two taxa is also different. Polygonum sawatchense subsp, oblivium has perianth lobe cells with anticlinal walls strongly sinuated and epicnticular wax pattern o f type 2, while subsp, sawatchense has anticlinal walls straight or weekly sinuate, and the epicuticular wax pattern of type 1. Polygonum sawatchense subsp, oblivium has also been frequently Confused with P. austiniae and P. minimum. From P. austiniae it differs through its erect and much larger flowers and achenes. From P. minimum it is distinguished by the morphology o f leaves and ocreae, stems, size of fruiting perianth and achenes, as well as the micromorphology of perianth. In particular, P. minimum has leaves that are hardly reduced distally, funnelform ocreae 1-4 m m long, papillae on stems and ocreae are conical, short, with a swollen base, and flowers and achenes are usually much smaller. Distribution and ecology. Western Canada (British Columbia) and western United States. It has the same ecology as subsp, sawatchense but unlike the latter may also grow in shaded or moist places. P h e n o l o g y . - - F l o w e r i n g June-August. 4. POLYGONUM ENGELMANNII Greene, Bull.

Calif. Acad. Sci. 1: 125. 1885. Polygon u m d o u g l a s i i subsp, e n g e l m a n n i i (Greene) Kartesz & Gandhi, Phytologia 68: 424. 1990. Polygonum tenue var. microspermum Engelm., Proc. Acad. Nat. Sci. Philadelphia 1863: 75. 1864. Polygonum microspermum Small, Bull. Torrey

Bot. Club STATES. gen Park, TYPE here

[VOL. 57 19: 366. 1892. TYPE: U N I T E D Colorado. Jefferson Co.: Ber14 Sep 1877, Greene s.n. (NEOdesignated: NDG).

Annual herbs. Stems 4 - 3 0 cm, green or purplish brown, freely branched from base, sparsely scaberulous-papillose on the ribs to almost glabrous; papillae conical, patent, 4 0 - 6 0 ixm, Leaves: basal leaves persistent at flowering, upper leaves abruptly reduced to scale-like bracts; ocreae 3-5 ram, funnelform, scaberulous-papillose to glabrous, free part becoming lacerate with age; blades linear-oblanceolate, 1 0 - 2 0 ( - 2 5 ) x 1-3(-4) mm; margins revolute, smooth; apex acute to mucronate. Papillae on the ocreae are similar to those present on the stems. Inflor e s c e n c e s terminal, e l o n g a t e spike-like thyrses, loose floriferous nearly to base; cymes (1-)2-4-flowered, regularly spaced along the stems and branches; bracts equaling or somewhat longer than the flowers. Flowers closed; pedicels reflexed, 1-3 mm; perianth 1.5-2(-2.5) mm; tube 18-26% of the perianth length, perianth lobes almost sepaloid, initially cucullate, later + flat, naviculate, forced apart by the developing achene (Fig. 3I), greenish or sometimes purple, with narrow white margins, midveins darker, unbranched; perianth lobe cells elongated, 4 5 - 6 5 • 5 - 8 Ixm, with the anticlinal walls strongly sinuate; epicuticular wax pattern o f type 2, with a narrow longitudinal pattern of reticulate rodlets at the top of cells (Fig. 5C). Stamens 5-8, anthers pink to purple, 128-158 txm, Pollen o f subtype A1, 22.3-23.7 /xm. Achenes elliptic, 1.2-2.3 ram, mostly exserted from the perianth at maturity, smooth. As in the case o f P. nuttallii (see below), the collection quoted by Hitchcock (1964) is formally typified here. Polygonum engelmannii is closely related to P. douglasii and P. austiniae. The three species have in common reflexed pedicels, short anthers, and the A1 subtype of pollen. However, the diminutive habit, small, funnelform ocreae, fruiting perianth, and achenes distinguish the former from P. douglasii. Although it may appear similar to P. austiniae, P. engelmannii is distinguished by its linear-oblanceolate leaves and exserted achenes. Ad-

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COSTEA & TARDIF: POLYGONUM DOUGLASII COMPLEX

ditionally, the three species have perianth lobes with a different pattern of organization of epicuticular waxes (Figs. 4B; 5A,

C). Distribution and ecology.~Canada (Alberta, British Columbia) and the United States (Colorado, Idaho, Montana, Nevada, South Dakota, Utah, and Wyoming). It grows in dry to moist, usually sandy or well drained soils, sandy gullies in prairie, from sagebrush deserts to lower mountains. Phenology.--Flowering June-September. 5. POLYGONUM AUSTINIAE Greene, Bull. Ca-

lif. Acad. Sci. 1: 212. 1885. Polygonum. douglasii var. austiniae (Greene) M. E. Jones, Contr. West. Bot. 12: 75. 1908. Polygonum douglasii subsp, austiniae (Greene) A. E. Murray, Kalmia 12: 23. 1982. TYPE: U N I T E D STATES. California (County not given): Goose Lake Valley, 1885, Austin s.n. (NEOTYPE designated by Hickman, 1984: NDG; ISONEOTYPE: US). Annual herbs. Stems 5 - 1 0 ( - 2 0 ) cm, 4angled, green to purplish, much branched from base, ascending to erect, scaberulouspapillose on the ribs; papillae white, conical 4 0 - 6 0 p~m. Leaves: basal leaves usually persistent at flowering, upper leaves abruptly reduced to scale-like bracts; ocreae 3-5 mm, funnelform, scaberulous-papillose or glabrous, free part lacerate; blades ovate to elliptic or obovate, 5-15 • 4 - 7 mm, margins plane or only very narrow revolute, denticulate-papillose; apex acute or mucronate. Papillae on ocreae and blades are similar to those on the stems. Inflorescences; lower cymes axillary, upper cymes in slender open spike-like thyrse; cymes 1-4flowered, regularly spaced along the stems and branches; bracts equaling or somewhat longer than the flowers. Flowers closed; pedicels reflexed, 1-2.5 mm; perianth (1.8)2-2.6 mm, tube 2 0 - 2 8 % of the perianth length, perianth lobes sepaloid or petaloid, cucullate, naviculate, overlapping (Fig. 3J), green or purple, with narrow, whitish margins; midveins darker, unbranched; perianth lobe cells elongated, irregularly branched to almost rectangular, 3 5 - 6 0 • 8-16 txm, with anticlinal walls moderately sinuate to al-

17

most straight; epicuticular wax pattern o f type 2, with a dense pattern of intertwined rodlets at the top of cells (Fig. 5A). Stamens 8, anthers pink to purple, 130-160 txm. Pollen of subtype A I , 20.1-23.3 txm. Achenes elliptic to slightly obovate, 2-2.5 mm, enclosed in the perianth at maturity, smooth or nearly so (Fig. 7G).

Distribution

and ecology.--Western

Canada (Alberta, British Columbia) and western United States. It grows in dry to moist flats on banks; from sagebrush plains to lower mountains, often in Ponderosa pine forests. Phenology.--Flowering June-September. 6. POLYGONUM MINIMUM S. Watson, Bot.

King Exp. 315. 1871. TYPE: U N I T E D STATES. Utah. Box Elder Co.: Bear River Canyon, 3200 m, Aug 1869, Watson 1058 (HOLOTYPE; US; ISOTYPES: NY, GH). Polygonum torreyi S. Watson, Amer. Nat. 7: 664. 1873. TYPE:UNITED STATES. California. Mariposa Co.: YosemiteValley, 1872, Torrey s.n. (HOLOTYPE: GH).

Annual herbs. Stems 2 - 3 0 cm long, 4angled, reddish brown, wiry, prostrate to erect, often zigzagged, simple or branched from base, scaberulous-papillose on and between the ribs; papillae red, orange or sometimes white, patent, conical with a swollen base, 4 0 - 6 0 Ixm (Fig. 1B). Leaves persistent at flowering, evenly distributed or crowded at branch tips, hardly reduced distally; ocreae funnelform, 1-4 mm, scaberulous-papillose, free part entire or dentatelacerate; blades narr6w-elliptic, elliptic, ovate, obovate, or subcircular, 6-27 X 3 - 8 mm; margins plane, irregularly thickened or denticulate-papillose (rarely glabrous), apex acute or mucronate. Papillae on the ocreae are often retrorse, similar to those on the stem; papillae on the leaf margins are white, conic-cylindrical, 100-180 txm, Inflorescences axillary; cymes 1-3-flowered starting from near stem and branch bases, sometimes also crowded at branch apices; bracts leaf-like, much longer than the flowers they subtend. Flowers semiopen or closed; pedicels erect to patent, 2-3 ram; perianth 1.82.5 mm; tube 2 2 - 2 9 % of the perianth length; perianth lobes almost sepaloid, cu-

18

BRITTONIA

cullate, naviculate to obscurely so, overlapping, green with narrow white or pink margins, midveins thickened, unbranched; perianth lobe cells are irregularly shaped, 3 5 45 • 10-16 txm with the anticlinal walls moderately sinuate; epicuticular wax pattern of type 1, with a dense pattern of reticulate and intertwined rodlets (Fig. 5E). Stamens 8; anthers purple, 120-165 txm. Pollen of subtype A2, 26-28.2 txm (Fig. 6E). Achenes elliptic to ovate, 1.8-2.3 mm, enclosed in the perianth at maturity, or only with the tip exserted, smooth. Although obviously related to P. douglasii, the specific status o f P. minimum has never been questioned as it has been for other similarly related species. The morphology o f anthers and pollen place P. minimum in close relationship to P. sawatchense subsp, oblivium, P. douglasii, P. engelmannii and P. austiniae. Some forms with narrow leaves approach P. nuttallii, with which P. minimum shares a c o m m o n morphology o f stems, ocreae, papillae, and pattern of epicuticular wax sculpture of perianth lobes. However, leaves of P. minimum are not glaucous adaxially, the margins are plane and denticulate-papillose, the flowers are mostly closed, and the pollen belongs to type A. Distribution and ecology.--Canada (Alberta, British Columbia) and the United States (Alaska, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming). It grows in alpine to subalpine communities, on open or semibarren soil; 1500-3300 m. Phenology.--Flowering July-September.

[VOL. 57

zagged, simple or branched, spreading to erect, scaberulous-papillose on and between the ribs (Fig. 1F); papillae red, orange or sometimes white, patent or retrorse, conical with a swollen base, 4 0 - 6 0 ~m. Leaves: basal leaves persistent at flowering, evenly distributed or crowded at branch tips, gradually transformed into bracts; ocreae 3 - 4 m m long, funnelform, scaberulous-papillose, free part finally lacerate; blades linear to narrow-elliptic, 8-30 • 1 - 4 ( - 7 ) mm, +_ glaucous adaxially; margins revolute, s m o o t h ; apex acute or acuminate. Papillae on ocreae are often retrorse, similar to those on the stems (Fig. IF). Inflorescences terminal, spiciform, dense and bracted; cymes with 2-3 flowers, aggregated at the apices of branches; bracts much longer than the flowers they subtend. Flowers semiopen or closed; pedicels erect or patent, 2-3 mm; perianth 1.8-2.4 mm; tube 2 5 - 3 3 % of the perianth length, perianth lobes petaloid, cucullate, usually naviculate only in the upper 1/4, + overlapping (Fig. 3C), pinkish green with pink borders, midvein greenish, unbranched; perianth lobe cells rectangular or irregularly shaped, 3 5 - 4 5 • 10-16 p~m with anticlinal walls moderately sinuate; epicuticular wax pattern of type 1, with a dense pattern o f reticulate and intertwined rodlets (Fig. 5F). Stamens 8; anthers purple, 2 5 0 - 3 2 5 jxm. Pollen o f type B, 27-29.2 txm (Fig. 6F). Achenes elliptic to ovate, 1.8-2.3 mm, e n c l o s e d in p e r i a n t h at maturity, smooth. Polygonum intermedium is illegitimate being a latter h o m o n y m for which Small (1895) proposed a new name, P. nuttallii. The collection designated as a lectotype was first quoted by Hitchcock (1964). Hick7. POLYGONUM NUTTALLII Small, Monogr. P o l y g o n u m 132, pl. 53. 1895. Polygo- man (1984) considered that Hitchcock efnum.intermedium Nutt. ex S. Watson, fectively lectotypified Polygonum nuttallii. Proc. Amer. Acad. Arts 17: 378. 1882. However, in Vascular Plants o f the Pacific P o l y g o n u m douglasii subsp, nuttallii Northwest, no names were typified unless (Small) J. C. Hickman, Madrofio 31: 250. specifically stated (Hitchcock et al., 1957). 1984. TYPE: UNITED STATES. Oregon To eliminate any doubt, the lectotype was (County not given). On bluffs of Colum- formally designed here. This distinct but u n c o m m o n species has bia River, Oct 1891, Pringle s.n. (LEETOTYPE, here designated: GH; ISOLECTO- been combined with P. douglasii (Hickman, 1984) because it was considered a TYPE: NY). small-flowered form of P. spergulariiforme, Annual herbs. Stems ( 5 - ) 1 0 - 3 5 cm long, as p r e v i o u s l y s u g g e s t e d b y H i t c h c o c k 4-angled, purplish, wiry, sometimes zig- (1964). Although similar to P. spergulari-

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C O S T E A & TARDIF: P O L Y G O N U M D O U G L A S I I C O M P L E X

iforme, P. nuttallii differs from the f o r m e r in m a n y respects: the stems are purplish and wiry, the ocreae are short with conical and swollen at base papillae, leaves are glaucous adaxially, bracts are m u c h longer than flowers, and the f r u i t i n g p e r i a n t h and achenes are short. Anticlinal walls of perianth lobe cells are moderately sinuate and the epicuticular w a x pattern belongs to type 1. Polygonum nuttallii has a c o m m o n morphology of stems, ocreae, papillae, and surface of perianth lobes with P. minimum. Distribution

and

ecology.--Western

Canada and western United States. It grows in dry "prairies" and open knolls in lower mountains, open sites in lowland and m o n tane zones, sandy soil at low elevations. Phenology.--Flowering M a y - O c t o b e r . 8. POLYGONUM SPERGULARIIFORME Meisn. e x

Small, Bull. Torrey Bot. Club 19: 366. 1892. Polygonum coarctatum Douglas ex J. M. Hook. var. minus Meisn. in DC., Prodr. 14: 101. 1856. Polygonum douglasii subsp, spergulariiforme (Meisn. ex Small) J. C. Hickman, Madrofio 3 1 : 2 5 1 . 1984. TYPE: U N I T E D STATES (Washington or Oregon). Hab. N.W. America. On the sandy banks of the C o l u m b i a and its branches, and on the higher branches of the Multnomak, Menzies s.n. (LECTOTYPE designated by Hickman, 1984: K n.v.).

Annual herbs. Stems 5 - 5 0 c m long, 4angled, green, divaricately branched, scaberulous on and between ribs (Fig. 1C) (rarely almost glabrous); papillae white, patent, dense, conical-elongate to cylindrical, 100-200 txm. Leaves: basal leaves usually caducous at flowering, upper leaves abruptly reduced to scale-like bracts; ocreae 8 - 1 2 m m , scaberulous-papillose, free part disintegrating into a few persistent fibers; blades linear to lanceolate, 3 5 - 6 0 • 1-3 m m , sometimes with scarce papillae (Fig. 2E); margins plane or very narrowly revolute, denticulate-papillose; apex acute or mucronate. Papillae on the ocreae and the margins of leaves are similar to those on the stems (Fig. 1C); papillae from the leaf blade are conical, shorter, 4 0 - 6 0 ixm, with a heavy cuticle (Fig. 2E). Inflorescences

19

t e r m i n a l , s p i c i f o r m , dense; c y m e s 2 - 5 flowered, crowded and • overlapping at branch tips; bracts equaling or s o m e w h a t longer than the flowers. Flowers open or semiopen; pedicel patent to erect, to 2 m m ; perianth 3 - 5 m m , tube 9 - 1 7 % o f the perianth length, perianth lobes petaloid, cucullate, usually naviculate only in the upper 1! 4 part, overlapping, pink or white, with broad pink borders; midveins green or brown, with short lateral branches; perianth lobe cells elongated, 5 0 - 6 5 • 6 - 9 txm with the anticlinal walls strongly sinuate; epicuticular wax pattern of type 2, with a narrow pattern of reticulate rodlets at the top o f cells (Fig. 4E). Stamens 8, anthers pink to purple, 4 0 0 - 5 5 0 p~m. Pollen of type B, 3 1 33 txm. Achenes narrow elliptic to elliptic lanceolate, 3 - 5 m m , enclosed in the perianth at maturity, smooth or tubercled (Fig. 7F). Plants with c y m e s spaced along the branches (not aggregated at branch apices) and the flowers m o r e or less patent or ascendent m a y be intermediates to P. majus, the closest related taxon. However, the reflexed achenes of the latter clearly separate the two taxa. Specimens annotated by Hickman (in herb.) as "intermediate between subsp, spergulariiforme and subsp, douglasii" belong to P. majus.

Distribution

and

ecology.--Canada

(southern British Columbia) and western United States. It grows in moist to dry, open rocky places (including serpentine); 10-2000 m. Phenology.--Flowering June-October.

9. POLYGONUMMAJUS (Meisn.) Piper, F1. Palouse Reg. 63. 1901. Polygonum coarctatum Douglas ex Meisn. var. majus Meisn. in DC., Prodr. 14: 101. 1856. Polygonum douglasii subsp, majus (Meisn.) J. C. Hickman, Madrofio 31: 250. 1984. TYPE: U N I T E D STATES (Washington or O r e g o n ) . " C o l u m b i a R i v e r , " 1830, Douglas s.n. (LECTOTYPE designated b y Hickman, 1984: GDC-n.v.; ISOLECTOTYPE: NY). Annual herbs. Stems 15-60 c m long, 4angled, g r e e n , erect, s i m p l y to f r e e l y branched, scaberulous-papillose on and be-

20

BRITTONIA

tween ribs; papillae white, patent or reflexed, dense, conical-elongate to cylindrical, 100-200 Ixm. Leaves: basal leaves often caducous at flowering, upper leaves abruptly reduced to scale-like bracts; ocreae 6 - 1 2 mm, scaberulous-papillose, free part lacerate or disintegrating into fibers; blades linear to narrowly oblong or lanceolate, 1570 • 2 - 8 mm; margins narrowly revolute, denticulate-papillose; apex acute or mucronate; papillae on the ocreae and leaf margins are similar to those on the stems. Inf l o r e s c e n c e s terminal, spike-like, open thyrses; cymes 2-5-flowered _+ uniformly spaced on stems and branches; bracts equaling or somewhat longer than the flowers. Flowers wide-open or semiopen; pedicels patent in flower and reflexed in fruit, 0.51 mm; perianth ( 3 . 5 - ) 4 - 5 mm; tube 9 - 1 7 % of the perianth length, perianth lobes petaloid, cucullate, naviculate only in the upper 1/4 part, overlapping, white or pink, borders white to pink; midveins green, unbranched or with short lateral branches; perianth lobe cells elongated, 4 5 - 6 0 • 6 - 9 txm, with the anticlinal walls strongly sinuate; epicuticular wax pattern of type 2, with a dense intertwined pattern o f reticulate rodlets at the top of cells (Fig. 4F). Stamens 8, anthers pink to purple, 4 0 0 - 5 0 0 Ixm. Pollen o f type B, 31-33 txm (Fig. 6H). Achenes elliptic, 3.5-5 mm, enclosed in perianth at maturity, smooth or tubercled (Fig. 7E). Distribution and ecology.--Canada (southern British Columbia) and western United States. It grows in dry plains, meadows (including serpentine) at elevations of 5 0 0 - 2 0 0 0 m. P h e n o l o g y . - - F l o w e r i n g May-August.

[VOL. 57

mm longa; inflorescentia terminalis densissima, 2 - 5 floribus axillaribus, pedicellis reflexis, p e r i a n t h i u m album, stamina 8; achaenia 1.8-2 mm longa, elliptica, inclusa vel paulo exserta. Differt a P. cascadense bracteis brevioribus paucioribus et pedicellis reflexis; difert a P. austiniae inflorescentia densissima, spiciformi, floribus apertis, perianthio albo, antheris longioribus. Annual herbs. Stems 3 - 1 0 cm long, 4angled, r e d d i s h g r e e n erect, z i g z a g g e d , branched below the middle, + glabrous. Leaves: basal leaves persistent at flowering, upper leaves gradually transformed into a few bracts; ocreae 2-5 mm, funnelform, glabrous, free part h y a l i n e __+ lacerate; blades oblanceolate, spathulate or obovate, 8 - 2 0 • 3-4.5 mm, margins plane or very narrowly revolute, smooth, apex acute to mucronate. Inflorescences terminal, spiciform, dense; cymes 2-5-flowered aggregated and overlapping at stem and branch apices; bracts scarce, shorter or equaling the flowers they subtend. Flowers wide-open (Fig. 3D); pedicels 0.5-2 ram, patent at flowering and reflexed in fruit; perianth 2.2-2.6 mm, tube 8 - 1 5 % o f the perianth length; perianth lobes petaloid, cucullate, naviculate, parallel (Fig. 3E), pure white, with green unbranched mid-veins (which may be brownish on dried material); perianth lobe cells are elongated, 5 5 - 6 5 • 8 12 Ixm, with the anticlinal walls strongly sinuate; epicuticular wax pattern of type 2, with a dense pattern of intertwined rodlets interrupted by small unsculputured spaces at the top o f cells (Fig. 5D). Stamens 8, anthers purple, 325-380 txm. Pollen of type B, 27.4-30.1 p~m (Fig. 6G). Achenes elliptic, 1.8-2 mm, enclosed or slightly exserted from the perianth at nmturity, smooth (Fig. 10. P o l y g o n u m gabrielae Costea & Tardif, 7I). Hickman (in herb.) identified collections sp. nov. (Fig. 8) TYPE: U N I T E D o f P. gabrielae as "P. cascadense with STATES. Oregon. Grant Co.: 7 mi S of Mt. Vernon, dry, barren, gravelly, north- characteristics of P. douglasii." Although f a c i n g s e r p e n t i n e slopes, o v e r l o o k i n g distinct, P. gabrielae shares some features Laycock Creek, T14S, R30E, $26, 1370 with P. austiniae and P. cascadense; howm, 29 Jun 1953, Cronquist 7330 (HOLO- ever, it differs by a dense terminal infloresTYPE: NY; ISOTYPES: MICH, MT, OSC, cence with overlapping cymes, wide-open flowers with white perianth lobes, anthers RSA, UC, WS). over 300 txm long, and pollen o f type B. In Annuum; caulis glaber, erectus, 3 - 1 0 cm contrast, P. austiniae has an open, elongataltus; folia oblanceolata vel obovata, 8-20 ed inflorescence with widely spaced cymes,

2005]

COSTEA & TARDIF: POLYGONUM DOUGLASII COMPLEX

21

lem

FIG. 8. Polygonumgabrielae, general habit (from Cronquist 7330, NY).

closed flowers, green or purple perianth lobes with narrow whitish margins, anthers shorter than 160 ixm, and pollen grains of type A. Polygonum gabrielae is easily distinguished from P. cascadense by the few and short bracts, perianth lobes naviculate along their entire length, and reflexed pedicels. The pattern of epicuticular wax sculpture in P. gabrielae is singular among the other species of Polygonum studied (Fig. 5D).

The species is named after Gabriela Costea, the senior author's wife. Distribution and ecology.--United States (rare in Oregon). Growing in dry, barren, gravelly serpentine slopes. More research will have to determine its exact distribution. Phenology.--Flowering June-August. 11. POLYGONUM CASCADENSE W. H. Baker, Madrofio 10: 62. 1949. TYPE: U N I T E D STATES. Oregon. Lane Co.: Calapooya

22

BRITTONIA R a n g e , F a i r v i e w M o u n t a i n , S slope, 1670 m, 28 Sep 1947, Baker 5129 (HOLOTYPE: O S C n.v.; ISOTYPES: CAS, US, NY, WS).

Annual herbs. Stems 5 - 1 2 ( - 1 5 ) cm long, 4-angled, green, wiry, zigzagged, angled, simple or branched from base, glabrous. Leaves: basal leaves persistent at flowering and gradually transformed into bracts; ocreae 2-5 mm, glabrous, free part is lacerate; blades oblanceolate to obovate, 5 - 2 0 • 2 5 mm; margins revolute, smooth; apex is rounded or mucronate. Inflorescences terminal, spiciform, bracteate, dense; cymes 3-5-flowered, congested at the tip o f stems and branches; bracts numerous, much longer than the flowers. Flowers wide-open; pedicels erect to patent, 2-3 mm; perianth 2-2.5 mm, tube 12-25% of the perianth length, perianth lobes petaloid, oblong to oblong-obovate, cucullate, naviculate only in the upper 1/~, overlapping (Fig. 3H), purewhite, m i d v e i n s pink or g r e e n i s h , unbranched; perianth lobe cells irregularly branched, 2 0 - 3 5 • 18-26 txm, with anticlinal walls strongly sinuate; epicuticular wax pattern o f type 1, with a dense pattern of intertwined, reticulate rodlets. Stamens 8; anthers purple, 325-350 ixm. Pollen of type B, 27.3-29.1 txm. Achenes ovate to o b l o n g - o v a t e , 1.8-2.1 mm, i n c l u d e d or slightly exserted from the perianth at maturity, smooth. Distribution and ecology.--United States (rare in the Cascade Mountains of Oregon). It grows on dry, usually rocky slopes, to 1800 m, often on serpentine. Phenology.--Flowering June-September. 12. POLYGONUMUTAHENSE Brenckle & Cottam, Bull. Univ. Utah 30: 3. 1940. Polygonum douglasii var. utahense (Brenckle & Cottam) S. Welsh, Utah Flora 3rd ed.: 518. 2003. TYPE: U N I T E D STATES. Utah. Garfield Co.: Escalante, 17 Sep 1935, Cottam 6507 (HOLOTYPE: UT; ISOTYPES: CAS, US, NY). D w a r f annual herb. Stems 1.5-3.5 cm long, 4-angled, erect, simple or with a few branches, papillose. Leaves 1-3, persistent at flowering; ocreae 2-3.5 ram, papillosescaberulous; free part hyaline, lacerate; leaf

[VOL. 57

blades erect, linear-subulate, coriaceous, uniformly papillose, 6 - 1 4 X 1 mm, + cylindrical due to revotute margins that join together on the lower side o f lamina (Fig. 2B); apex mucronate. Papillae on stems and leaves are short, conical, 2 5 - 4 0 p,m (Fig. 2F). Inflorescences are terminal, spiciform, bracteate, dense; cymes 2-4-flowered, starting almost from stem base, overlapping; bracts much longer than the flowers. Flowers wide-open; pedicels erect, 0.4-1 mm; perianth 2-2.5 mm, tube 2 0 - 2 5 % of the perianth length; perianth lobes petaloid, oblong to wide obovate, cucullate, naviculate only in the upper 1/~, overlapping (Fig. 3G); pure white, midvein green or brownish, branched; perianth lobe cells elongated, 5 5 70 X 8-11 p~m, with anticlinal walls strongly sinuate; epicuticular wax pattern of type 2, with a dense pattern of intertwined rodlets at the top of cells (Fig. 5B). Stamens 8, anthers purple to dark-brown, 3 5 0 - 4 2 0 p,m. Pollen of type B, 27.5-28.9 p,m. Achenes 1.5-2 mm, elliptic, included in the perianth, smooth (Fig. 7J). Polygonum utahense has been considered a synonym o f P. sawatchense subsp, sawatchense (e.g., Welsh, 1987; Kartesz, 1998). Recently it has been combined with P. douglasii as a variety (Welsh, 2003). However, the morphology o f perianth, anthers, and pollen place it more closely to P. cascadense, from which it is distinguished by the dwarf habit and the papillose ocreae, stems, and cylindrical leaves. Distribution and ecology.--United States (known only from Garfield Co., Utah). Growing in dry, sandy ravines, to 2300 m, on rocky Navajo sandstone spur. Phenology.--Flowering July-September. Discussion The 12 species can be usually clearly separated using morphological characters. Morphology of achenes, which is so important for the species of section Polygonum, is less significant for the relatives of P. douglasii. Micromorphological characters bring in new data that support the recognition of the members of P. douglasii complex as species. Hong and Oh (1999) reported that section Duravia is character-

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COSTEA & TARDIF: POLYGONUM

ized by leaf epidermal cells with undulate anticlinal walls, and our study confirms this finding. M i c r o m o r p h o l o g y of leaf epicuticular wax has little taxonomic significance and is useful only in P. utahense, which exhibits a pattern o f reticulate rodlets. Papillae are c o m m o n structures encountered on stems and leaves of these species. Their presence or absence, and sometimes their morphology, is useful to distinguish some taxa. The surface of perianth lobes has proven to be interesting because in another study, H o n g et al. (1998) found that "cuticular striation alone does not appear to have much systematic v a l u e " in the tribes Polygoneae and Persicarieae. However, the authors studied only two species (and two collections) from this group (P. douglasii and P. spergulariiforme). Our results indicate that except for P. majus-P, spergulariiforme and P. minimum-P, nuttallii, which are v e r y similar in this respect, the other taxa are quite distinct. Indeed, the micromorphology of perianth lobes surface is remarkably diverse and allows the distinction o f most taxa. Hedberg (1946) suggested that the " D u ravia type of pollen is derived f r o m the Avicularia-type," and that this type of pollen evolved independently in Polygonum and Polygonella. In this respect, the subtype A1 of pollen m a y considered the most primitive form of Duravia pollen because it is morphologically the closest to the Avicularia-type. Pollen of subtype A2 m a y be considered intermediate to the " t y p i c a l " Duravia-type (type B). Plants are self-pollinating, but differences in floral and pollen m o r p h o l o g y suggest that different species m a y have developed different pollination strategies. Based on the m o r p h o l o g y of flowers, anthers and pollen, two directions of evolution m a y be recognized: The first, the "douglasii g r o u p " (P.

douglasii, P. sawatchense, P. engelmannii, P. austiniae, and P. minimum) has flowers usually closed (but sometimes open), anthers 9 0 - 1 9 0 p,m, and pollen of type A. The second, the " m a j u s g r o u p " (P. majus, P. spergulariiforme, P. nuttallii, P. cascadense, P. gabrielae, and P. utahense) has flowers open, anthers 2 5 0 - 4 5 0 p~m, and

DOUGLASII COMPLEX

23

pollen of type B. These two groups overlap slightly. For example, P. majus is related to P. douglasii and P. spergulariiforme; P. nuttallii shares affinities with both P. minimum and P. spergulariiforme; P. gabrielae is related to both P. austiniae and P. cascadense. It m a y be possible that the evolution of these species has been, at lest to some extent, reticulate. However, no matter how these taxa evolved, the current evidence supports their treatment as species.

Acknowledgments We are indebted to G u y N e s o m and one a n o n y m o u s reviewer w h o contributed with helpful criticism and suggestions that improved earlier versions o f the manuscript. We thank curators f r o m the herbaria cited f o r p r e p a r i n g the ( u s u a l l y ) v o l u m i n o u s loans. We are grateful to Sandy Smith w h o facilitated the S E M study. Barbara Hellenthal and Crcile Aupic helped us to locate some of the type collections.

Literature Cited Barthlott, W., C. N e i n h u i s , D. C u t l e r , F. Ditsch, I. M e u s e l , I. T h e i s e n & H. W i l h e l m i . 1998. Classification and terminology o f plant epicuticular waxes. Bot. J. Linn. Soc. 126: 237-260. Costea, M. & F. J. T a r d i f . 2003a. Typification, taxo n o m y and a n e w subspecies of Polygonum sawatchense (Polygonaceae) from North America. Sida 20: 1631-1640. - - . 2003b. Nomenclatural changes in the genus Polygonum s.str. (Polygonaceae). Sida 20: 9 8 7 997. H a r a l d s o n , K. 1978. A n a t o m y and t a x o n o m y in Polygonaceae, subfam. Polygonoideae Meisn. e m e n d Jaretzky. Acta Univ. Upsaliensis 22: 1-95. Hedberg, O. 1946. Pollen morphology in the genus Polygonum L. s. lat. and its taxonomical significance. Svensk Bot. Tidskr. 40: 3 7 1 - 4 0 4 . H i e k m a n , J. C. 1984. Nomenclatural changes in Persicaria, Polygonum and Rumex (Polygonaceae). Madrofio 31: 2 4 9 - 2 5 2 . - - . 1993. Polygonaceae. Pages 854-895. In: J. C. Hickman, editor. T h e Jepson manual: higher plants o f California. U n i v e r s i t y o f California Press, Berkeley, California. H i t e h e o e k , C. L., A. C r o n q u i s t & M. O w n b e y . 1957. Vascular plants o f the Pacific Northwest. Part 1. Cryptogams, G y m n o s p e r m s and Monocotyledons. University of W a s h i n g t o n Press, Seattle, Washington. Hitchcock, C. L. 1964. Polygonum. Pages 140-168. In: C. L. Hitchcock, A. Cronquist, M. O w n b e y & J. W. T h o m p s o n , editors. Vascular Plants of the Pacific Northwest. Part 2. Salicaceae to Saxifraga-

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ceae, University of Washington Press, Seattle, Washington. Hoen, P. 1999. Glossary of pollen and spore terminology. Laboratory of Palaeobotany and Palynology, Utrecht. http://www.bio.uu.nl/-palaeo/glossary/glos-int.htm Hong, S.-P., L. P. Ronse Deeraene & E. Smets.

1998. Systematic significance of tepal surface morphology in tribes Persicarieae and Polygoneae (Polygonaceae). Bot. J. Linn. Soc. 127: 91-116. Hong, S.-P. & I. C. Oh. 1999. The taxonomic study of leaf epidermal microstructure in the genera Polygonum s.str, and Polygonella Michx. (Polygonaceae). Korean J. P1. Tax. 29: 75-90. Kartesz, J. T. & K. N. Gandhi. 1990. Nomenclatural notes for the North American flora lI. Phytologia 68: 421-427. Kartesz, J. T. 1998. A synonymized checklist of the vascular flora of the United States, Puerto Rico, and the Virgin Islands. Full Text Index. http:// www.csdl.tamu.edu/FLORA/b98/check98.htm L6ve, A. & D. Liive. 1956. Chromosomes and taxonomy of eastern North American Polygonum. Can. J. Bot. 34: 501-521. Mertens, T. R. & P. H. Raven. 1965. Taxonomy of Polygonum section Polygonum (Avicularia) in North America. Madrofio 18: 85-92. Appendix

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Ronse Decraene, L. P. & J. R. Akeroyd. 1988. Ge-

neric limits in Polygonum and related genera (Polygonaceae) on the basis of floral characters. Bot. J. Linn9 Soc. 98: 321-371. , S.-P. Hong & E. Smets. 2000. Systematic significance of fruit morphology and anatomy in tribes Persicarieae and Polygoneae (Polygonaceae). Bot. J. Linn. Soc. 134: 301-337. Small, J. K. 1895. A monograph of the North American species of the genus Polygonum. Lancaster, Pennsylvania. Welsh, S. L. 1987. Polygonaceae. Pages 470-4939 In: S. L. Welsh, A. D. Atwood, S. Goorich & L. C. Higgins, editors. A Utah flora. Great Basin Nat. Mem. 9: 1-894. Brigham Young University, Provo, Utah. 9 2003. Polygonaceae. Pages 497-521. In: S. L. Welsh, N. D. Atwood, S. Goodrich & L. C. Higgins, editors9 A Utah flora (3rd ed., revised)9 Marcus Jones Endowment Fund, Brigham Young University, Provo, Utah. Wolf, S. J. & J. McNeill. 1986. Synopsis and achene morphology of Polygonum section Polygonum (Polygonaceae) in Canada. Rhodora 88: 457-479. - & - - . 1987. Cytotaxonomic studies on Polygonum section Polygonum in eastern Canada and the adjacent United States. Can. J. Bot. 65: 647-652.

1. V o u c h e r s f o r t h e S E M S t u d y

1. Polygonum tenue. U N I T E D S T A T E S . Connecticut. Middlesex Co.: Portland, B u c k t o w n , 4 S e p 1896, S t a r m e r s.n. (NY). Illinois. M a s o n Co.: N e a r H a v a n a , 15 S e p 1929, C h a s e s.n. (DS); P u t n a m Co.: S E Putn a m , 5 S e p 1949, C h a s e 10827 ( N Y ) . I o w a . A l l a m a k e e Co.: I o w a T o w n s h i p , 3 m i E o f N e w A l b i n , 13 S e p 1937, H a y d e n 5028 ( N Y ) . M a s s a c h u s e t t s . M i d d l e s e x Co.: W o burn, H o r n P o n d Hill, 11 O c t 1935, S m i t h & H o d g d o n s.n. (DS). N e w Jersey. O c e a n Co.: F o r k e d River, 18 S e p 1932, A l e x a n d e r s.n. ( N Y ) . O h i o . L u c a s Co.: N o f C r i s s e y , j u n c t i o n o f F r a n k f o r t a n d M e i l k e R o a d s , 25 Jul 1995, C u s i c k 3 2 6 1 0 & S c h n e i d e r ( N Y ) . P e n n s y l v a n i a . L a n c a s t e r Co.: C o n e w a g o , 1 S e p 1892, H e l l e r s.n. ( N Y ) . S o u t h D a k o t a . M i n n e h a h a Co.: M i n n e h a h a , D e l l R a p i d s , 24 A u g 1946, B r e n c k l e s.n. ( C A S ) . Tenn e s s e e . G r u n d y Co.: ca. 10 m i N o f T r a c y City, j u n c t i o n T e n n e s s e e 56 a n d 108, 29 S e p 1971, K r a l 4 4 5 3 7 ( N Y ) . W i s c o n s i n . R i c h l a n d Co.: 2 m i W o f B l u e River, 205 m, 12 A u g 1977, N e e 15698 ( N Y ) ; W a u shara C o . : 2 m i W o f C o l o m a , 22 A u g 1940, S h i n n e r s & C a t e n h u s e n 2 6 5 7 ( N Y ) . 2. Polygonum douglasii. CANADA.

S a s k a t c h e w a n . G r a s s l a n d N a t i o n a l Park: 10 m i S E o f Val M a r i e , 17 Jul 1989, H o o p e r & Ledingham 10836 (USAS); Cypress Hills, C e n t e r B l o c k , 29 A u g 1987, H u d s o n 4765 ( U S A S ) . U N I T E D S T A T E S . C a l i f o r nia. E l d o r a d o Co.: n e a r C a m p E c h o , L i n c o l n H y w . , 2 1 3 0 m, 6 A u g 1915, H e l l e r 12188 ( G H ) . M o n t a n a . G l a c i e r Co.: G l a c i e r National Park, vicinity of Belton (now c a l l e d W e s t G l a c i e r ) , 9 4 6 - 9 8 0 m, 3 - 4 S e p 1919, S t a n d l e y 18705 ( N Y ) . N e w H a m p shire. C a r o l l Co.: A l b a n y , S a n t a M o a t Mt., 11 Sep, 1949, S e e l e s.n. ( G H ) ; C o 6 s Co.: H a r t ' s L e d g e , H a d l e y ' s G r a n t , 9 S e p 1915, P e a s e s.n. ( N E B C i n ' G H ) . O r e g o n . B a k e r Co.: B l u e Mts., S side o f m e a d o w s a b o u t Mud Lake, Anthony Lakes, Elkhorn Ridge, 9 A u g 1946, M a g u i r e & H o l m g r e n s.n. ( N Y ) . U t a h : ( C o u n t y n o t g i v e n ) E l k Mts., n e a r S c o r u p ' s C a m p , 2 5 0 0 m, 8 A u g 1911, R y d b e r g & G a r r e t t 9553 ( N Y ) . V e r m o n t . A d d i s o n Co.: A d d i s o n , S n a k e M a n , 1878, B r a i n e r d s.n. ( G H ) ; R u t l a n d Co.: W o f Rutland, 12 S e p 1912, K i r k s.n. ( N E B C in GH). 3a. P o l y g o n u m sawatchense Small subsp, sawatchense. U N I T E D S T A T E S .

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Arizona. C o co ni no Co.: Buch Springs Ranger Station, 2290 m, Sep 1936, Collom 599 (US); Flagstaff, 2 Aug 1884, Jones 3957 (RSA); Cochise Co.: Chiricahua Mts., Coronado National Forest, S base of Barfoot Peak, 2500 m, 4 Sep 1983, Ward & Peterson s.n. (RSA). California. Lassen Co.: Harvey Valley, 9 Jul 1934, Howell 12528 (RSA); Riverside Co.: Santa Rosa Peak, Virgin Springs, 2290 m, 14 Aug 1938, Munz 15359 (RSA); San Bernardino Co.: San Bernardino Mts., bellow Dollar Lake, 2650 m, 22 Aug 1922, Munz 6190 (RSA). Colorado. Conejos Co.: 7 mi N of Conejos Campground, NW of Antonito, 19 Jul 1952, Weber 7862 (RSA); Larimer Co.: Moraine Park, 11 Aug 1925, Osterhout 6464 (RSA). Nevada. Clark Co.: Charleston Mts., Charleston Park, 2270 m, 29 Jul 1938, Clokey 7901 (RSA); Humboldt Co.: Pine Forest Range, 11 mi N of Leonard Creek Ranch, 1950 m, 27 Jun 1964, Holmgren & Reveal 1120 (RSA). New Mexico. San Miquel Co.: T. M. O'Connor Ranch, South Rim Pasture, 2100 m, 1.5 mi E of Las Vegas, 28 Jul 1984, Hill 14631 (RSA); Valencia Co.: Mt. Taylor, San Mateo Mts., College experimental area, 20 mi E of Grants, 2530 m, 4 Sep 1935, Parker 2333 (RSA). Wyoming. Crook Co.: Bear Lodge Range, Reuter Canyon, 5 mi N of Sundance, 1770 m, 12 Jul 1960, Porter & Porter 8374 (RSA). MEXICO. Baja California: Sierra, San Pedro Martir, Dead Horse Meadow, SW end of Venado Blanco, 17 Jul 1988, Boyd et al. 2628. (RSA). 3b. Polygonum sawatchense subsp, oblivium. Canada. British Columbia: Road up to Windy Joe, Manning Park, 1470 m, 4 Aug 1957, Beamish 7856 (GH). uNITED sTATES, california. Nevada Co.: Castle Peak, 31 Jul 1903, Heller s.n. (GH); Siskiyou Co.: Grass Lake, 18 Jul 1948, Mason 13623 (RSA); Rocky summit, ridge road to Deadwood Lookout, mountains W of Yreka, 25 Jun 1952, Ownbey & Preece, Jr. 3345 (NY). Idaho. Elmore Co.: W side Lava Mt. at headwaters of Russell Gulch, Boise National Forest N of Smith Prairie, 2290 m, 15 Jul 1981, Ertter & Grimes 4531 (RSA). Nevada. Elko Co.: hillsides above Maggie Summit, Bull Run Mts., 2040 m, 20 Jun 1980, Grimes et al. 1646 (NY);

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Humboldt Co.: Sonoma Range, Water Canyon, 2070 m, 10 Jul 1964, Holmgren & Reveal 1374 (NY). Oregon (County not given): Achoco Forest, 22 Jun 1932, Peck 17068 (NY); Josephine Co.: summit of the Siskiyou Mts., 1370 m, 21 Jun 1922, Heller s.n. (NY); Lake Co.: Willow Creek Forestry Camp, Warner Mts., 1770 m, 24 Jun 1973, Munz 18361 (RSA). Washington. Asotin Co.: ridge leading N of Big Butte on the breaks of the Grand Ronde River, 1520 m, 3 Jun 1939, Meyer 1622 (GH). 4. Polygonum engelmannii. U N I T E D STATES. Colorado. Boulder Co.: near Boulder, 1520-1830 m, Jul 1902, Tweedy s.n. (NY); E1 Paso Co.: Manitou (Springs?), 2100 m, 1 Aug 1901, Clements & Clements s.n. (DS); Pikes Peak, below Mountain View, 1 Aug 1943, Ewan 15145 (CAS). Idaho (County not given): Little Bear Creek, 13 Aug 1942, Degener & Peiler 16834 (NY). Montana. Carbon Co.: Beartooth Mts., NW above bridge across Hell Roaring Creek, 2770 m, 12 Aug 1977, Lackschewitz 7826 (NY). Wyoming. Albany Co.: Jelm Mt., just below the summit, 28 Aug 1977, Hartman & Hammel 4965 (CAS); Morton's Pass, NE of Bosler, 18 Jul 1950, Ripley & Barneby s.n. (CAS); E of Laramie, 2190 m, 22 Jun 1943, Porter s.n. (NY); Lone Tree Pass, Laramie, 21 Jul 1939, Brenckle & Mellete 39-02 (NY). 5. Polygonum austiniae. U N I T E D STATES. California. Lassen Co.: Diamond Mts., Diamond Peak, 2350 m, 3 Jul 1989, Schoolcraft 1946 (UC). Idaho. Gooding Co.: N of Clover Creek Rd. between Hill City and Bliss, SW sitle of Davis Mt., in the Bennett Hills, 12 Jun 1981, Ertter 4190 (NY). Oregon (County not given): near head of Dry Creek, 1650 m, 6 Jun 1896, Leiberg 2208 (NY); Harney Co.: 100 mi SE of Burns, S tributary to Alvord Creek, well up on the E side of Steens Mts., 2440 m, 30 Jun 1959, Cronquist 8588 (NY); W slope of Steens Mts., 28 Jun 1942, Peck 21454 (NY). Montana. Lewis and Clark Co.: off the Bear Creek Rd., meadow in the Bear Creek Canyon, 20 Jut 1982, Lackschewitz & Ramsden 10034 (NY). Nevada. Elko Co.: Rocky Mts., Jarbidge, 2130 m, 6 Jul 1912, Nelson & Macbride s.n. (NY); Eureka Co.: Robert Creek Mts., ridge E of

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BRITTONIA

Robert's Creek, 4 Aug 1984, Tiehm & Nachlinger 9129 (NY); Humboldt Co.: N side of Hinkey summit, Martin Creek, 2190 m, 28 Jun 1975, Williams & Tiehm 1212 (NY). 6. Polygonum minimum. CANADA. Alberta: Rocky Mts., Lake Louise, 7 Aug 1919, Hunnevel 6305 (GH). United States. California. Fresno Co.: Hutchinson Meadow Area, 10 mi E of Florence, 3690-3810 m, 21 Aug 1955, Quibell 5949 (GH); Inulare Co.: between East Lake and Reflection Lake, 5 Aug 1940, Howell s.n. (CAS); Mendocino Co.: Anthony Peak, 8 Aug 1943, Howell 19195 (DS); Trinity Co.: N Yolla Bolly Mts., 20 Jul 1951, Munz 16734 (DS); Tulare Co.: Kaweah Peaks, near Soda Spring, Big Arroya Soda Springs Trail, 28 Jul 1987, Dudley s.n. (DS). Montana. Flathead Co.: Sperry Glacier, 1 Sep 1903, Umbach 823 (GH). Nevada. Washoe Co.: Carson Range, Sierra Nevada, stream draining Ginny Lake, 27 Jul 1976, Tiehm 2596 (CAS). Oregon. Marion Co.: Breitenbush, 12 Jul 1935, Peck 18827 (CAS). Washington. Grays Harbor Co.: Bob Mt., 1250 and 1400 m, 27 Jul 1934, Rossbach & Hodgdon s.n. (GH); Pierce Co.: Mount Rainier National Park, 16 Aug 1963, Hitchcock s.n. (DS). 7. Polygonum nuttallii. CANADA. British Columbia: ca. 10 mi E of Bella Coola on road to Anahim Lake, 21 Aug 1956, Calder et al. 20322 (CAS); Chilliwack Valley, between 49 ~ and 49~ 121025 ' and 122~ 9 Aug 1906, Spreadborough s.n. (NY). United States. Oregon. W Oregon, Aug 1880, Howell s.n. (CAS); Clackamas Co.: 60 mi E of Portland, near Bonneville Dam, mouth of Tanner Creek, 14 Aug 1982, Neese et al. 12234 (NY); Columbia Co (?).: St. Helen, Oct 1882, Howell s.n. (CAS, NY). Washington: Mason Co.: Lake Cushman, gravel bar of Skokomish River, Aug 1895, Piper s.n. (NY); Skamania Co.: Cape Horn, 18 Aug 1894, Suksdorf 2288 (NY) 8. Polygonum spergulariiforme. CANADA. British Columbia: Vancouver Island, Hats, Parksville, Sep 1915, Carter s.n. (CAS). United States. California. Del Norte Co.: Sasquet, 17 Sep 1912, Eastwood s.n. (CAS); Humboldt Co.: Bald Hills, Knee-

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land, 15 Sep 1930, Parks & Tracy 767 (DS); Ireka Co.: 23 Oct 1922, Eastwood s.n. (CAS); Lassen Co.: Blacks Mt. Experimental Forest, 1800 m, 29 Jul 1964, Quick s.n. (CAS); Matin Co.: Dillons Beach, 6 Sep 1947, Howell s.n. (CAS); Nevada Co.: Donner Lake, 1830 m, 10 Aug 1931, Peirson 9564 (CAS); Shasta Co.: Clark Creek Rd., just W of Hwy. 89, 9 Jul 1986, Anderson 3114 (CAS); Sierra Co.: road from Dog Valley Summit to Hobart Mills, turn to Verdi Peak, 1830 m, 29 Aug 1976, Williams 76-106 (CAS); Siskiyou Co.: near Wagon Creek Falls, E side of Mt. Eddy, 1370 m, 20 Jul 1916, Heller s.n. (CAS). Oregon. Curry Co.: Gold Beach, Nov 1915, Hoyt s.n. (DS); Josephine Co.: summit of Siskiyou Mts., 1370 m, 21 Jun 1922, Heller s.n. (DS). Washington. Skamania Co.: between Cooks and Hood, 14 Oct 1925, Suksdoff s.n. (DS). 9. Polygonum majus. United States. Idaho. Adams Co.: 20 mi SE New Meadows, near Hwy. to Weiser, 24 Jun 1946, Hitchcock & Muhlick s.n. (DS); Canyon Co.: Big Willow, 28 May 1910, Macbride 133 (DS); Idaho Co.: 1.6 mi E of Slate Creek, 28 Jun 1950, Jones 126 (DS); Nez Perces Co.: near Lewiston, 29 May 1896, Heller & Heller s.n. (DS). Oregon. Baker Co.: Roadside banks along Pine Creek, 11 Jun 1950, Cronquist 6550 (DS); Umatilla Co.: 11 mi E of Pendelton on road to Meacham, 21 Jun 1935, Keck & Clausen 3599 (DS); Wallowa Co.: 5 mi NE of Elgin, 17 Jul 1946, Maguire & Holmgren s.n. (DS). Washington. Asotin Co.: 1 mi SE of Anatone, 18 Jun 1949, Cronquist & Jones 5859 (DS); Klickitat Co.: 1.7 mi Dallesport, 13 Sep 1987, Halse 3522 (CAS); Lincoln Co.: 3 mi above Grand Coulee Dam,. S side of Columbia River, 18 May 1940, Rogers 461 (CAS); Whitman Co.: Wawawai, 27 Jun 1933, Thompson 9242 (DS). 10. Polygonum gabrielae. U N I T E D STATES. Oregon. Grant Co.: 7 mi S of Mt. Vernon, N-facing slopes, overlooking Laycock Creek, T14S, R30E, $26, 1370 m., 29 Jun 1953, Cronquist 7330 (NY). 11. Polygonum cascadense. United States. Oregon. Klamath Co.: 17 mi W of Crater Lake, 31 Jul 1916, Peck 6245 (GH); Crater Lake National Park, 1680 m, 17 Jul

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COSTEA & TARDIF: POLYGONUM DOUGLASII COMPLEX

1936, "J.S." 67 (UC). Lane Co.: Mouth, French Pete Creek, S Fork McKenzie, 1700 m, 26 Jun 1967, Hickman 399-1 (UC); Rebel Rock, 30 Jun 1965, Hickman 145-2 (JEPS); Linn Co.: Iron Mt., 1.5 mi N of

27

Tombstone summit, 15 Aug 1957, Steward 7336 (GH). 12. Polygonum utahense. U N I T E D STATES. Utah. Garfield Co.: Escalante, 17 Sep 1935, Cottam 6507 (CAS).