Three new species of Cobaea (Polemoniaceae) L . A L A N PRATHER 1

Prather, L. A. (Herbarium, Department of Botany, University of Texas, Austin, TX 78713-7640, U.S.A.). Three new species of Cobaea (Polemoniaceae). Brittonia 48:111-119. 1996.--Revisionary work has revealed three new species of Cobaea: Cobaea flava of northern Peru, C. paneroi of central Mexico, and C. rotundiflora of Guatemala and extreme southeastern Mexico. Cobaea flava is most similar to C. campanulata and differs mainly in its pedicel pubescence, corolla coloration, and stamen position. Cobaea paneroi is among the large-flowered species (the Cobaea scandens group) but is easily distinguished from these by its long-acuminate calyx segments. Cobaea rotundiflora most closely resembles C. triflora. It differs mainly in its corolla coloration and wider, pubescent calyx segments. Estudios taxon6micos en el gtnero Cobaea han revelado la existencia de tres especies huevas para la ciencia: Cobaea tiara del norte del Peril, C. paneroi de Mtxico central, y C. rotundiflora de Guatemala y el extremo suroriental de Mtxico. Cobaea tiara es muy similar a C. campanulata, de la que difiere principalmente por la pubescencia del pedicelo, el color de la corola y la posici6n de los estambres. Cobaea paneroi se encuentra entre la especies de flores grandes (grupo Cobaea scandens), peru se distingue facilmente de 6stas por sus segmentos del c~liz que son largamente acuminados. Cobaea rotundiflora se asemeja principalmente a C. triflora de la que se diferencia principalmente por el color de la corola y la pubescencia de los segmentos del c~liz. Key words:

Polemoniaceae, Cobaea, Guatemala, Mexico, Peru.

Cobaea Cav. is a neotropical genus of approximately 18 species that is typically treated as a m e m b e r of the Polemoniaceae (e.g., Brand, 1907; Cronquist, 1981; Grant, 1959; Standley, 1914), a l t h o u g h s o m e workers have placed it in the monotypic family Cobaeaceae (G. Dahlgren, 1989; R. Dah~gren, 1980; Don, 1824; Hutchinson, 1973). Cobaea is clearly monophyletic and is easily distinguished from other genera of Polemoniaceae by several synapomorphies: a c l i m b i n g habit; p i n n a t e l y c o m p o u n d leaves with the terminal leaflets modified as tendrils; large, campanulate flowers; free calyx segments; extremely large (102-233 ~m), reticulate pollen; and septicidal fruits i Current address: Department o f Ecology and Evolutionary Biology, University o f California, Irvine, C A 92717, U.S.A.

(Prather, 1995). Cobaea is one o f only three genera in the Polemoniaceae that occurs in mesic, tropical-montane environments, typically cloud forests, and the only one that has a broad neotropical distribution. Because o f its rarity and tropical distribution, it is one o f the least studied genera in this well-known family. Revisionary studies have revealed three new species, all belonging to sect. Cobaea, which is defined by its erect pedicels and broad corolla lobes (Grant, 1959). Two belong to a group of species that have small flowers and narrow, chartaceous calyx segments. With the exception o f C. minor M. Martens & Galeotti, all o f the small-flowered species have terete style branches with short papillae covering nearly the entire surface (Fig. 1) and few-flowered dichasial

Brittonia, 48(1), 1996, pp. 111-119. 9 1996, by The New York Botanical Garden, Bronx, NY 10458-5126

ISSUED: 21 March 1996

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D 2 cm

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FIGo 1. Cobaeaflava (Stork 11395, GH). A, Upper style and style branches. B. Cross section of style branch. The lower part of the diagram is the abaxial surface. C. Portion of the habit. D. Front view of flower. cymes (following Weberling, 1989). The l o n g papillae only on their adaxial surface stigma shape is shared with the species o f (Fig. 2)_ This group, which consists o f about seven species, is also characterized the two remaining sections, Aschersoniophila Bra~d and Rosenbergia (Oerst.) A. by large, fleshy flowers which are typically Peter. The s~yle branches of C. minor and solitary in the leaf axils, and broad and/or the species of ~he large-flowered group of coriaceous calyx segments. Because o f their distinctive morphologisect. Cobaea, to which the third new species belongs, are broad, flattened, and have cal characters, in combination with a distri-

1996]

PRATHER: P O L E M O N I A C E A E

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bution consisting o f contiguous populations, the new taxa deserve specific rank. Furthermore, the distributions o f two o f the three new taxa are allopatric to all other Cobaea species. Cobaea paneroi is the exception, s o m e t i m e s o c c u r r i n g s y m p a t r i c a l l y with C. stiputaris Benth.

m m wide, narrowly lanceolate, twisted after dehiscence. Style 2 8 - 4 3 m m long; style branches 3.5-7 m m long, terete, with short papillae covering nearly the entire surface. Fruit 3 2 - 4 7 m m long. Seeds 9 - 1 5 per fruit, 9 - 1 3 m m long, 6 - 8 m m wide, lacking scales.

C o b a e a f l a v a Prather, sp. nov. (Fig. 1)

occurs typically in the lower montane forests o f the Andean I Region (sensu Gentry, 1993) at elevations of 1000-1500 m. This elevational range is lower than that o f m o s t species of Cobaea. A notable exception is the related Cobaea campanulata Hemsl., that occurs at 2 0 0 - 4 0 0 m in the lowland rain forests o f Ecuador. Etymology. Cobaeaflava is so n a m e d because of its distinctive corolla color. This is the only species o f the genus that has flowers that are truly yellow when fresh, although two others h a v e greenish yellow flowers. Oddly, C. lutea D. Don, a different species with an epithet implying a yellow color, is m i s n a m e d ; it consistently has green flowers.

Habitat and Distribution. Cobaea flava TYPE: PERU. Dept. Piura, Prov. A y a v a ca: Valley o f the river Quirds, 1500 m, M a y 1912, Weberbauer 6397 (HOLOTYPE: GH; tSOTYPES: E U S - - 2 sheets). Cobaeae campanulatae HemsL similis sed trichomatibus pedicellorum usque ad 4 mm longis praesertim ad basim pedicelli (nec 1 mm hand tibus longioribus), corollis flavis (nec viridibus re1 flavoviren lineis purpureis re1 rubris), et staminibus inclusis (nee exsertis) differt.

Stems herbaceous, glabrous or occasionally with long scattered trichomes, especially at the nodes. Leaves green; rachis 2 5 - 5 3 m m long, glabrous; petiolules 3 - 6 m m long, glabrous; blades 3 7 - 8 5 m m long, 1 6 49 m m wide~ elliptic to obovate, base acuminate to cordate, ciliate on the lowest leaflet pair, pubescent along the abaxial veins, apex acute to acuminate. Inflorescence a dichasial c y m e o f 1-5 flowers, subtended b y a pair o f fully expanded foliaceous bracts: Peduncles 6.7-11 c m long, glabrous. Pedicels 10.5-16 c m long, sometimes curved in fruit, pilose at the base and apex with tric h o m e s up to 4 m m long, occasional trichomes along length. Calyx segments green, 18-23 m m long, 4 - 6 m m wide, lanceolate to slightly oblanceolate, acute to acuminate, ciliate with both long and short trichomes, sometimes tomentutose near apex adaxially, with a few long scattered trichomes abaxially. Corollas light yellow or white, m e m b r a n o u s , funnelform to narrowly campanulate, glabrous externally near base, increasingly glandular-puberulent toward apex; tubes 3 0 - 4 0 m m long, 17-29 m m wide, widest at apex; lobes 1 1 17 m m long, 10-15 m m wide, widely ovate, apex rounded, emarginate. Stamens included; filaments 2 3 - 3 4 m m long, neither coiling or b e c o m i n g undulate after anther dehiscence, converging on the ventral side o f the corolla; anthers 4-8.5 m m long, 1 - 2

Additional specimens examined: PERU. Dept. Piura: N o v . AYAVACA:W slopes of Andes below Frias, May 1912, Weberbauer 6425 (F, GH, US); Arriba de los Caracnchos (Sullana-Ayabaca), 25 May 1971, Ldpez et aL 7705 (US); PROV. HUANCABAMBA:Distrito Canchaque, Chorro blanco, 18 Apr 1987, Dfaz S. & Baldedn 2469 (F, MO, N-Y); immediately W of Canchaque, 4 Apt 1939, Stork 11395 (GH, UC). Dept. Tumbes: Cerros de Amotape, Quebrada Los Conejos and adjacent ridge, ca. 25 km SE of Cherrelique, l0 Jun 1987, Gentry & Dgaz S. 58300 (MO, TEX).

Cobaea tiara m o s t "closely resembles C. campanulata (Table I): both have rounded, emarginate corolla lobes and anthers that are clustered at the ventral side o f the corolla. The species differ in the p u b e s c e n c e o f their pedicels, color o f their corollas, length o f their corolla tubes, position of their stamens, and f o r m o f their filaments (Table I). There has been a great deal o f confusion concerning the three small-flowered species of sect. Cobaea occurring in South America; C. campanulata, C. flava, and C. lutea. Three o f the above-cited sheets o f C. flava were cited as the only vouchers o f C. campanulata in Flora of Peru (Gibson, 1967), and one of t h e m was cited as the only voucher of C. lutea in the Catalogue of the

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Flowering Plants and Gymnosperms of Peru (Brako & Zarucchi, 1993). Cobaea campanulata is apparently endemic to Ecuador, even though m a n y treatments and floras cite it as being in Peru (Brako & Zarucchi, 1993; Gibson, 1967) and Chile ( B r a n d , 1907; S t a n d l e y , 1914; G i b s o n , 1967). The Chilean reports are evidently a result o f Brand (1907) confusing A t a c a m e s in Ecuador (the type locality) with the Ata c a m a Desert of northern Chile. Cobaea campanulata was k n o w n f r o m only two collections until several workers collected it at the Rfo Palenque Science Center in Ecuador within the last 30 years. To further complicate the matter, the specimens f r o m the Rfo Palenque Science Center were mistaken for C. lutea (Dodson & Gentry, 1978). All the specimens, or duplicates thereof, cited as C. lutea have been examined and are in fact C. campanulata. Because the illustration and description were compiled f r o m the cited specimens, they fit C. campanulata well. Examination o f specimens of the type collection of C. campanulata m a d e it apparent that the specimens f r o m Peru were an undescribed taxon and that the n a m e C. carnpanulata properly refers to the species f r o m Ecuador. Cobaea lutea is present in central Peru (Woytkowski 7330; M O - - 2 sheets, UC), but [ h a v e seen no collections of the species f r o m northern Peru where C. tiara occurs, nor f r o m Ecuador where C. campanulata occurs. Cobaea flava and C. campanulata differ f r o m C. tutea by the shape of their corolla lobes, length o f their style branches, and position of their anthers (Table I). C o b a e a par~eroi Prather, sp. nov. (Fig. 2) TYPE: M E X I C O . Est. Hidalgo, Mpio. Tenango de Doria: 5 k m N E de Tenango de Doria, 1690 m, 5 Jul 1979, Herndndez M. 3332 (HOLOTYPE: M E X U ; ~SOTYeES: M E X U , MO). Cobaeae scandenti Car. simflis sed foliolo basali acuminato re1 tmncato (nec auriculato) et sepalis angustioribus (14-16 mm Jarls nec 22-35 ram) ovatis vel lanceolatis (nee late ovatis) apice longi-acuminatis (nec obtusis) differt.

S t e m s w o o d y , v i l l o u s at the n o d e s . Leaves green suffused with purple; rachis

[VOL. 48

28-61 m m long, sparsely and minutely puberulent; petiolules 2 - 7 m m long, puberulent; blades 4 6 - 1 0 3 m m long, 2 3 - 4 4 m m wide, obovate to elliptic to broadly elliptic, sometimes slightly constricted in center, puberulent along the abaxial veins, base acuminate to truncate, glabrous on the lowest leaflet pair, apex acuminate. Inflorescence a solitary flower, subtended by a pair o f poorly developed bracts. Peduncles 1-4 cm long, puberulent. Pedicels 7 - 1 4 c m long, neither undulate or coiled in fruit, puberulent at base and sometimes slightly so along the length and at the apex. Calyx segments green, 2 0 - 2 7 m m long, t 4 - 1 6 m m wide, ovate to lanceolate, long-acuminate, with a broad zone of dense pubescence adaxially, sparsely puberulent abaxially. Corollas white, tinted with purple or purple throughout, chartaceous, campanulate, eglandularvillous near base, increasingly glandularpuberulent toward apex; tube 3 5 - 3 8 m m long, 3 3 - 3 6 m m wide, widest at apex; lobes 15-18 m m long, 2 3 - 2 5 m m wide, broadly ovate, apex rounded. Stamens included; filaments 4 5 - 5 5 m m long, b e c o m i n g undulate after dehiscence, converging on the ventral side of the corolla; anthers 7 - 9 m m long, 1 - 2 m m wide, narrowly oblong, not twisted after dehiscence. Style 4 0 - 4 5 m m long; style branches 4 - 5 m m long, broad, flat, with long papillae on the inner surface only. Fruit 4 5 - 5 5 m m long. Seeds several per fruit, 10-15 m m long, 7 - 1 2 m m wide, furnished with scales.

Habitat and Distribution.--Cobaea paneroi is similar to all other slSecies of the C. scandens group in that it occurs in tropical-montane cloud forests. Its distribution is apparently limited to eastern Hidalgo and adjacent Puebla, Mexico. Etymology. Cobaea paneroi is n a m e d in honor o f Dr. Jos4 Panero o f Michigan State University, a specialist in the Asteraceae and Latin A m e r i c a n floristics. His collections of Cobaea f r o m Ecuador, Venezuela, and Mexico have proven invaluable to m y studies; equally appreciated are his encouragement, wm'mth, and humor. Additional specimens examined: MEXICO: Est. Hidalgo, Mpio. Tenango de Doria, 9 km E de Tenango de Doria, hacia Tutotepec, 21 Feb 1981, Herndndez M. 5536 (MEXU, MO); Est. Puebla, along hwy. 130 ca.

1996]

PRATHER: POLEMONIACEAE

5 krn by road S from Xicotepec de Juarez, 16 Oct 1969, Dieterle 3642 (MICH). Cobaea paneroi belongs to the taxonomically difficult Cobaea scandens group. It is confined to an area in central Mexico between populations o f C. stipularis in Hidalgo and C. scandens Car. in Veracruz. Cobaea paneroi is distinguished from all other species of Cobaea by its long-acuminate calyx segments. Further characters distinguishing it from C. scandens and C. stipularis are given in Table II. Cobaea rotundiflora (Fig~ 3)

Prather, sp. nov.

TYPE: M E X I C O . Est. Chiapas, Mpio. Motozintla de Mendoza: S W side of Cerro Mozotal, 11 k m N W o f the jct. of the rd. to Motozintla along the rd. to E1 Porvenir and Siltepec, steep canyon, montane rain forest with Oecopetalum, Magnolia, Clethra, Pinus, Ouercus, and Symplocos, 2100 m, 21 N o v 1976, Breedlove 4 ] 6 4 7 (NOLOTYPE: TEX; ~SOaWPES:DS, MO). Cobaeae triflorae Donn. Sm. similis sed calycis segmentis latioribus (8-12 mm nec 5-7 ram) pilosis vel villosis (nec glabris) et corollis pigmento purpurascenti carentihus differt. Stems herbaceous, villous at the nodes. L e a v e s green; rachis 4 0 - 8 5 m m long, sparsely puberulent; petiolules 6 - 1 2 m m long, puberulent; blades 3 5 - 8 0 m m long, 15-33 m m wide, obovate to elliptic to ovate, base acute to slightly cordate, ciliate on the lowest leaflet pair, apex acute to acuminate. Inflorescence a dichasial cyme o f 1-4 flowers, subtended by a pair of fully expanded foliaceous bracts. Peduncles 6 . 5 12 c m long, puberulent at the base and along the length, villous at the apex. Pedicels 17-29 cm long, slightly undulate in fruit, villous at base with trichomes up to 4 m m long, nearly glabrous along length, puberulent at apex. Calyx segments green, suffused with brown or red in center, 2 4 33 m m long, 8 - 1 2 m m wide, widely lanceolate, acute, ciliate with both long and short trichomes, essentially glabrous adaxially, pilose to villous or rarely glabrous abaxial~y. Corollas yellowish green or occasionally yellow, chartaceous, campanulate, externally eglandular-villous at base

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(rarely glabrous) and throat, increasingly g l a n d u l a r - p u b e r u l e n t t o w a r d apex; tubes 2 1 - 2 8 (36) m m long, 2 2 - 3 0 m m wide, widest below the apex; lobes 10-13. (17) m m long, 11-17 m m wide, deltate, apex imbricate, acute. Stamens about equalling the corolla tube or slightly exceeding it; filaments 2 7 - 2 9 m m long, coiling after anther dehiscence, converging on the ventral side o f the corolla; anthers 7.5-8 m m long, 1.5 m m wide, narrowly oblong, twisted after dehiscence. Style 4 2 - 4 9 m m long; style branches 5 - 7 m m long, terete, with short papillae covering nearly the entire surface. Fruit 3 4 39 m m long. Seeds 10-15 per fruit, 14-18 m m long, 8 - 1 0 m m wide, lacking scales. Habitat and Distribution. The habitat o f C. rotundiflora is among the drier ones occupied by Cobaea species. It is found mainly at elevations o f 1900-2800 m in the montane rain forest vegetational formation within the Sierra Madre physiographic reg i o n a c c o r d i n g to the c l a s s i f i c a t i o n o f Breedlove (1981), but the Guatemalan collection was from an area of tropical deciduous forest. While only 3 5 - 4 0 km from the sites in Mexico, this site is much lower in elevation and borders the central depression that is covered by tropical deciduous forest ( B r e e d l o v e , 1981). In D e c e m b e r 1991, nearly all o f the w o o d y vegetation at the Guatemala site was bare o f leaves and the aboveground portions o f C. rotundiflora were mostly dry. I was able to locate only a few leaves and fruit (Prather 960). The species has a very limited distribution in the M u n i c i p i o M o t o z i n t l a de M e n d o z a in southern Chiapas and across the border NE into Guatemala. Etymology. The epi~&et ~ was chosen to emphasize the almost spherical corolla tube, which is unique in the genus. Additional specimens examined: MEXICO. Est. ChlapaNo MPIO. MOTOZINTLA DE MENDOZA: 45--50 k m

NE of Huixtla along rd. to Motozintla, steep slopes with montane rain forest, 17 Nov 1971, Breedlove & Smith 22689 (DS, ELL, MICH, MO); 45-50 km NE of Huixtla along rd. to Motozintla, steep slopes with montane rain forest, 28 Dec 1972, Breedlove & Thorne 31096 (DS, MO, TEX); Rancho Nuevo, 6 km al SE de E1 Rosaria, bosque, ladera de cerro, 2 Feb 1987, Ventura & Ldpez 4255 (MO). GUATEMALA. DepL tIuehuetenango: Along

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C

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Ft~. 3. Cobaea rotundiflora (from living material grown from seeds of Prather 960, TEX). A. Corolla segment showing internal pubescence and post-dehiscence stamen, B. Flower. C. Portion of the habit.

1996]

PRATHER: POLEMONIACEAE

Central American Hwy. 1, ca. 1.6 km E of the Mexico/ Guatemala border at Cuauhtemoc and La Mesilla, tropical forest on steep hillsides, 26 Dec t99t, Prather 960 (TEX). C o b a e a rotundiflora is s i m i l a r to C. trif l o r a D o n n . Sin. o f A l t a a n d B a j a Verapaz, G u a t e m a l a , i n the s h a p e o f their c o r o l l a lobes, c o r o l l a tube size, style lengths, a n d f o r m o f the f i l a m e n t s (Table I). H o w e v e r , they differ i n p e d i c e l a n d c a l y x p u b e s c e n c e , c a l y x width, a n d c o r o l l a w i d t h a n d c o l o r (Table I). P l a n t s g r o w n f r o m seed c o l l e c t e d i n G u a t e m a l a ( P r a t h e r 960, TEX) are atypical i n that they lack a n y p u b e s c e n c e e x t e r n a l l y n e a r the b a s e o f the c o r o l l a a n d o n the abaxial side o f the c a l y x s e g m e n t s , a l t h o u g h they are ciliate as i n the other s p e c i m e n s . I n all other aspects they are s i m i l a r to the s p e c i m e n s f r o m Chiapas. I n c u l t i v a t i o n , the Guatemalan plants were self-pollinating a n d s e l f - c o m p a t i b l e , setting a b u n d a n t fruit i n the a b s e n c e o f a n y a p p a r e n t m a n i p u l a t i o n or visitation, w h i l e other species i n cultiv a t i o n failed to do so. T h e s t a m e n s a n d style b r a n c h e s are c l u s t e r e d at the v e n t r a l side o f the c o r o l l a j u s t b e y o n d the tube. A f ter a n t h e r d e h i s c e n c e , p o l l e n was transferred directly to the style b r a n c h e s t h r o u g h c o n t a c t with the anthers.

Acknowledgments I a m grateful to G u y N e s o m for p r o v i d i n g the L a t i n d i a g n o s e s . T h e i l l u s t r a t i o n s were p r o v i d e d b y Piero D e l p r e t e a n d the r e s u m e n b y 3avier F r a n c i s c o - O r t e g a . B. L. T u r n e r read the m a n u s c r i p t a n d m a d e m a n y h e l p f u l s u g g e s t i o n s . R o b e r t P a t t e r s o n carefully r e v i e w e d the m a n u s c r i p t , a n d h e a n d the editor, L i s a M. C a m p b e l l , i m p r o v e d it c o n s i d e r a b l y . R u p e r t C. B a r n e b y also m a d e m a n y helpful suggestions. Finally I thank the curators o f the f o l l o w i n g h e r b a r i a for l o a n s o f s p e c i m e n s : DS, E G H , LL, M E X U ,

119

M I C H , M O , NY, T E X , U C , US. F i n a n c i a l support was provided by National Science Foundation grant D E B - 9 4 1 2 1 7 4 and by a 1994 G a r d e n C l u b o f A m e r i c a / W o r l d W i l d life F u n d S c h o l a r s h i p i n T r o p i c a l B o t a n y .

Literature Cited Brako, L. & J. L. Zarucehi. 1993. Catalogue of the flowering plants and gymnosperms of Peru. Monogr. Syst. Bot. Missouri Bot. Gard. 45. Missouri Botanical Garden, St. Louis. Brand, A. 1907. Polemoniaceae. Pages 2-181. In: A. Engler, editor. Das Pflanzeureich IV.250 (Heft 27). Breedlove, D. E. 1981. Flora of Chiapas: Pt. 1. Introduction to the flora of Chiapas. California Academy of Sciences, San Francisco. Cronquist, A. 1981. An integrated system of classification of flowering plants. Columbia University Press, New York. Dahlgren, G. 1989. The last Dahlgrenogram--system of classification of the dicotyledons. Pages 249260. In: K. Tan, editor. The Davis & Hedge Festschrift. University Press, Edinburgh. Dahlgren, R. 1980. A revised system of classification of the angiosperms. J. Linn. Soc., Bot. 80: 91-124. Dodson, C. H. & A. H. Gentry. 1978. Flora of the Rfo Palenque Science Center. Selbyana 4: 1-628. Don, D. 1824. Observations on a new family of plants to be called Cobeaceae. J. Edinburgh Phil. Soc. 7: 283-291. Gentry, A. H. 1993. Overview of the Peruvian flora. pages xxix-xl. In: L. Brako & J. L. Zarncchi, editors. Catalogue of the flowering plants and gymnosperms of Peru. Monogr. Syst. /3ot. Missouri Bot. Gard. 45. Missouri Botanical Garden, St. Louis. Gibson, D. 1967. Flora of Peru: Polernoniaceae. Fieldiana, Bot. 13: 112-131. Grant, V. 1959. Natural history of the Phlox family. Nijhoff, The Hague. Hutchinson, J. 1973. The families of flowering plants arranged according to a new system based on their probable phylogeny. Ed. 3. Clarendon Press, Oxford. Prather, L. A. 1995. Evolution of floral morphology and systematics of Cobaea (Polemoniaceae). Ph.D. dissertation. University of Texas, Austin. Standley, P. C. 1914. A revision of the genus Cobaea. Contr. U.S. Natl. Herb. 17: 448458. Weberling, F. 1989. Morphology of flowers and inflorescences. University Press, Cambridge.