A new species of Sicyos L. (Cucurbitaceae) from Oaxaca, Mexico ISELA RODR[GUEZ-ARIffVALO, RAFAEL LIRA, AND ISMAEL CALZADA
Rodrfguez-Ardvalo, I.*, R. Lira & I. Calzada (Unidad de Biotecnologfa y Prototipos, Universidad Nacional Autdnoma de M6xico, Campus Iztacala, Avenida de los Barrios s.n. Los Reyes lztacala, Tlalnepantla, Estado de M6xico, C.R 54090, M6xico; e-mail*:
[email protected]). A new species of Sicyos L. (Cucurbitaceae) from Oaxaca, Mexico. Brittonia 57: 43-46. 2005.--Sicyos mcvaughii, a new species from Oaxaca, is described and illustrated. It is similar to Sicyos sertuliferus Cogn., and grows in secondary tropical deciduous forest, between 20 and 630 meters. Key words:
Cucurbitaceae, Mexico, Oaxaca, Sicyos.
The Cucurbitaceae are represented in Mexico by 141 species and subspecific taxa (Lira et al., 2002), grouped into two subfamilies and 34 genera. The genus Sicyos is one of the most diverse within the family. In his most recent classification, Jeffrey (1990) placed Sicyos in subfamily Cucurbitoideae, tribe Sicyeae, subtribe Sicyinae (along with Sicyosperma, Parasicyos, Microsechium, Sechium, Sechiopsis, and Pter-
osicyos). According to Jeffrey (1990), Sicyos consists of ca. 40 species. In the last five years a revision of Mexican Sicyos has been accomplished (Rodrfguez-Ar6valo, 2001). As a result of this revision, five new species have been described (Lira & Rodriguez-Ar6valo, 1999; Rodrfguez-Ar6valo & Lira, 2001; R o d r f g u e z - A r 6 v a l o , 2003; R o d r f guez-Ar6valo et al., 2004). We are herein proposing an additional new species f r o m Oaxaca, which raises the number of species of Sicyos k n o w n f r o m Mexico to 17. Sicyos m c v a u g h i i Rodrfguez-Ar6valo, Lira & Calzada, sp. nov. (Fig. 1) TYPE: M E X I C O . C h i a p a s : M u n i c i p i o Santa Marfa Huatulco, en la desviaci6n a Huatulco, carretera Salina Cruz-Puerto Angel, 15~ 96~ 62 m, 12
N o v 1999, L Rodrfguez-Ardvalo & J. L Calzada 297 (HOLOTYPE:M E X U ; ISOTYPES: E N C B , IEB, IZTA, M I C H , MO, NY, XAL). Herba repens vel scandens. Folia ovato-triangularia valde acuminata. Flores staminati 5-meri, antheris exsertis. Flores pistillati 5 - 7 - m e r i , stigmate exserto 3 4-1obo, lobis rotundatis vel ovoideis, reflexis. Sicyo sertulifero similis, sed f m c t i b u s siccis triangulari-ovoideis, spinis caducis differt.
Scandent m o n o e c i o u s herb, creeping and c l i m b i n g b y tendrils; s t e m s slender, branched, sulcate, glabrous to sparsely villous at the nodes. Leaves simple, thin, m e m b r a n o u s to p a p y r a c e o u s , b r o a d l y ovate-triangular, 5-7-angulate-lobed, 3 . 5 17 • 3.3-19.6 cm, the lobes wide, triangular, the central lobe longer than the lateral, strongly acuminate, the margin serrulate-denticulate, both surfaces strigose, abaxial surface with the veins more prominent and the trichomes shorter; petioles 0 . 7 - 6 c m long, sulcate, sparsely to densely glandular-villous; tendrils long-stalked, 2 . 6 - 1 0 c m long, sulcate, 3-6-branched, sparsely to densely glandular-villous. Staminate inflorescence in the same axil as the pistillate, panicles, racemes o f umbels, or a combination of both, 7.6-40.5 c m long, erect; peduncle 6.2-22.7 c m long; rachis densely glandular-pubescent toward the apex; pedicels slender, 2.9-10.6 m m long, ascendant,
Brittonia, 57(1), 2005, pp. 4 3 4 6 . 9 2005, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.
ISSUED: 31 March 2005
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FIG. 1. Sicyos mcvaughii. A. Habit. B. Staminate flower. C. Pistillate flower. D. Fruit (Rodrlguez-Ar~valo & Calzada 297, M E X U )
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TABLE I COMPARISON OF THE MORPHOLOGICAL CHARACTERISTICS OF Characteristics
Staminate inflorescence Stigma Fruit
Fruit armature
Sicyos mcvaughii
Sicyos mcvaughii
Acicular, antrorse, retrorsely barbed, all caducous
Additional specimens examined. MEXICO. OAXACA. Mpio. Santiago Astata, Distrito de Tehuantepec, Istmo, por Pie del Cerro, 2 km al NE de Barra de la
Sicyos sertuliferus
Sicyos sertuliferus
Panicles, racemes of umbels or a combination of both 3-4-lobed, the lobes rounded to ovoid Dry, triangular-ovoid, slightly rostrate, 0.8-1 cm long, 0.3-0.6 cm in diameter, densely armed
densely glandular-pubescent villous; flower receptacle 5-rnerous, narrowly campanulate, 0 . 6 - 2 m m l o n g , 0 . 8 - 3 m m w i d e ; c a l y x l o b e s subulate, 0 . 2 - 0 . 4 m m long; c o r o l l a g r e e n i s h y e l l o w , 5 - m e r o u s , the l o b e s triangular, 1 - 3 • 0 . 5 - 2 m m , the m a r g i n s a n d adaxial surface densely glandular-villous; s t a m e n s f u s e d into a c o l u m n 2 . 5 - 4 . 7 m m long, the filaments forming a central colu m n , the a n t h e r s u n i t e d f o r m i n g a g l o b o s e h e a d , the t h e c a e c u r v e d . P i s t i l l a t e i n f l o r e s cence umbelliform; peduncle 1-2.2 cm l o n g , e l o n g a t i n g to 5.5 c m in fruit, d e n s e l y glandular-villous. Pistillate flowers numerous; o v a r y u n i l o c u l a r , o v o i d , s l i g h t l y rostrate, a r m e d , d e n s e l y g l a n d u l a r - p u b e s c e n t v i l l o u s ; o v u l e 1, o c c u p y i n g a l m o s t the entire locule; r e c e p t a c l e a n d p e r i a n t h s m a l l e r t h a n t h o s e o f the s t a m i n a t e flowers; c o r o l l a w i t h 5 - 7 petals; c o l u m n o f style a n d s t i g m a 2.5 m m l o n g ; s t i g m a s c o n s p i c u o u s l y e x serted, 3 - 4 - l o b e d , the l o b e s r o u n d e d to o v o i d , reflexed. F r u i t s n u m e r o u s , d r y , 0 . 8 1 c m long, 0 . 3 - 0 . 6 c m in diameter, t r i a n g u l a r - o v o i d , s l i g h t l y rostrate, d e n s e l y a r m e d e x c e p t for the r o s t r u m ; fruit w a l l thin, s t r o n g l y a t t a c h e d to the seed, light to d a r k b r o w n i s h ; s p i n e s 2 - 6 . 3 m m long, acicular, antrorse, c a d u c o u s , r e t r o r s e l y b a r b e d , y e l lowish. Seed ovoid, compressed, dark brown. Distribution.--At present, Sicyos m c v a u g h i i has b e e n c o l l e c t e d o n l y in O a x a c a , M e x i c o , in s e c o n d a r y t r o p i c a l d e c i d u o u s forest, at e l e v a t i o n s b e t w e e n 20 a n d 630 meters.
AND
Racemes of umbels 3-lobed, the lobes triangular Dry, ovoid, 0.8-1.4 cm long, 0.2--0.6 cm in diameter, with some verrucose, antrorse projections mainly at the base, glabrous Acicular, antrorse, retrorsely barbed, some caducous "and some persistent
Cruz, 15~ 95~ 20 m, 31 Oct 1998, M. Elorsa 1021 (MEXU); Mpio. San Miguel del Puerto, Distrito de Pochutla, San Isidro Chacalapa, 3.5 km N por brecha hacia Chongo, paso el rfo Chacalapa, 15~ 95~ 230 m, 25 Oct 1999, C. Perret et al. 671 (MEXU); Zimat~in, 7 km por la carretera a Huatulco, desviaci6n de la Garza, 15~ 96~ 30 m, 23 Oct 1999, J. Rivera et al. 2013 (MEXU); Km 234 de la carretera Huatulco-Pochutla, 15~ 96~ 74 m, 12 Nov 1999, /. Rodr{guez-Ardvalo & J. L Calzada 298 (MEXU); La Merced del Potrero, 4 km S, 3.8 km de la brecha, camino al Colorado Grande, 16~ 96~ 630 m, 28 Oct 1999, S. Salas et al. 2510 (MEXU). S i c y o s m c v a u g h i i is c l o s e l y r e l a t e d to S. s e r t u l i f e r u s C o g n . , w i t h w h i c h it shares e x serted stamens and stigmas, and similar o v o i d fruits. N e v e r t h e l e s s , S. m c v a u g h i i c a n b e d i s t i n g u i s h e d f r o m S. s e r t u l i f e r u s b y its staminate inflorescences, which consist of panicles, racemes of umbels, or a combin a t i o n o f b o t h , its r o u n d e d to o v o i d s t i g m a lobes, a n d its c a d u c o u s fruit a r m a t u r e . In contrast, S. s e r t u l i f e r u s has s t a m i n a t e inflor e s c e n c e s g r o u p e d e x c l u s i v e l y in r a c e m e s of umbels, triangular stigmatic lobes, and a combination of caducous and persistent s p i n e s on the fruit. In a d d i t i o n the t w o s p e cies have different distributions: S. m c v a u g h i i h a s b e e n c o l l e c t e d o n l y in O a x a c a , w h e r e a s S. s e r t u l i f e r u s is k n o w n f r o m C o s t a R i c a a n d a l o n g the Pacific C o a s t o f M e x i c o in the states o f C o l i m a , G u e r r e r o , J a l i s c o , a n d M i c h o a c a n . M o r p h o l o g i c a l diff e r e n c e s b e t w e e n the s p e c i e s a r e s u m m a r i z e d in T a b l e I. T h e n e w s p e c i e s is n a m e d in h o n o r o f Dr. R o g e r s M c V a u g h (b. 1909), w h o h a s c o n t r i b u t e d i m m e n s e l y to k n o w l e d g e o f t h e M e x i c a n flora.
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Acknowledgments W e w i s h t o t h a n k Dr. F e r n a n d o C h i a n g (MEXU), who prepared the Latin description and made comments on the manuscript. T h e i l l u s t r a t i o n o f Sicyos m c v a u g h i i w a s made by Jestls Moctezuma Garcia. Funds for this research were provided to the first author by the Consejo Nacional para la Ciencia y la Tecnologfa (CONACyT), through the master's thesis scholarship CONACyT-92140.
Literature Cited Jeffrey, C. 1990. Appendix: an outline classification of the Cucurbitaceae. Pages 449-463. In: D. M, Bates, R. W. Robinson & C. Jeffrey, editors. Biology and utilization of the Cucurbitaceae. Cornell University Press, Ithaca, New York.
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Lira, R. & I. Rodrlguez-Arrvalo. 1999. Nuevas especies de los grneros Cyclanthera Schrad. y Sicyos L. (Sicyeae, Cucurbitaceae) para la flora de Mrxico. Acta Bot. Mexicana. 48: 11-19. , J. L, Villasefior & E. Ortiz. 2002, A proposal for the conservation of the family Cucurbitaceae in Mexico. Biodiversity and Conservation 11: 1699-1720. Rodrlguez-Arrvalo, I. 2001. Revisirn del grnero Sicyos L. (Cucurbitaceae) en Mrxico. Tesis de Maestr/a. Facultad de Ciencias, Universidad Nacional Aut6noma de Mrxico, M~xico, D.E 9 2003. A new species of Sicyos (Cucurbitaceae, Sicyeae, Sicyinae) from Mexico and Guatemala. Brittonia 55(1): 69-72. - & R. Lira. 2001. Nueva especie del grnero Sicyos L. (Cucurbitaceae) para la Repfiblica Mexicana. Bol. Soc. Bot. Mrxico 68: 81-84. , - , & P. D~ivila. 2004. Two new species of Sicyos L. (Cucurbitaceae) from Guerrero and Oaxaca, Mexico. Bot. J. Linn, Soc. 145: 373-378.
