Pteropepon (Cogn.) Cogn.
Pteropepon (Cogn.) Cogn. Pflanzenr. IV 275 (Heft 66): 260. 1916.
Type: Pteropepon monospermus (Vell.) Cogn.; basionym: Fevillea monosperma Vell., Fl. Flumin. 10, t. 103. 1827 (1831).
Sicydium sect. Pteropepon Cogn., in Martius, Fl. Bras. 6: 112. 1878.
Pseudosicydium Harms, Notizbl. Bot. Gart. Berlin-Dahlem 10: 182. 1927.

Perennial climbers with herbaceous or woody shoots, tuberous roots, and monoecious or dioecious sex system. The leaves are simple, petiolate, with subdeltoid, subcircular or subcordate, entire or 3-5-lobed blade, or subtruncate with two lateral punctate glands just above the insertion of the petiole at the base. The tendrils are apically bifid. The flowers are small. Male flowers are produced in panicles or thyrses, female flowers stand solitary or few are grouped in monochasia or panicles. The receptacle-tube is saucer-shaped with five linear, or deltoid to lanceolate sepals. The corolla is rotate with five ovate-lanceolate, whitish, greenish or yellowish petals, which are fused at the base. The 1-3 stamens are inserted at the base of the tube on short, recurved, free filaments, less often filaments absent or fused into a central column. The anthers are very variable in the genus: either all are monothecous or two anthers are bithecous plus one monothecous or one anther is bithecous plus one monothecous or there is just one single bithecous anther. The thecae are straight, horizontal and contain tricolporate, striate, small pollen (polar axis 33-35 µm, equatorial axis 27-32 µm (Khunwasi 1998)). The ovary is oblong, strongly compressed subtrigonous, monolocular with an apical placenta and one pendent ovule. The three styles carry three bifid stigmata. The fruit is a large, fibrous samara with one continuous, encircling wing or the fruit is small, compressed, membranaceous, with two lateral wings, standing solitary or in groups of 2-3. The seed is solitary, pendent, compressed with verrucous or scrobiculate testa.

The six species are found in humid ravines close to rivers, in primary rain forest and secondary scrub in South America from Argentina to Brazil and Colombia.

Pteropepon is sister to the genus Sicydium from which it split about 39 million years ago (Schaefer et al. 2009). Both are placed in the tribe Triceratieae (Schaefer & Renner 2011).

Accepted species

Pteropepon acariaeanthus (Harms) H. Schaef. & S.S. Renner, Taxon 60: 135. 2011.
Pteropepon argentinense Mart. Crov., Bol. Soc. Argent. Bot. 4: 189. 1952.
Pteropepon deltoideus Cogn., Pflanzenr. 275: 260. 1916.
Pteropepon monospermus (Vell.) Cogn., Pflanzenr. 4, 1: 260. 1916.
Pteropepon oleiferum Cogollo & Pipoly, Sida 16: 402. 1995.
Pteropepon parodii Mart. Crov., Bol. Soc. Argent. Bot. 3: 174. 1950.


Cogollo, A. and J.J. Pipoly III. 1995. Una nueva especie del género Pteropepon (Cucurbitaceae) de Colombia. Sida 16: 401-406.

Jeffrey, C., 1962. Notes on some species of Fevillea L., Siolmatra Baill., and Pseudosicydium Harms (Cucurbitaceae) in the Amazon Basin. Kew Bull. 16: 199-202.

Martínez Crovetto, R. 1952. El género Pteropepon (Cucurbitaceae) en la República Argentina. Bol. Soc. Argent. Bot. 4: 177-182.

Schaefer, H. and S.S. Renner. 2011. Phylogenetic relationships in the order Cucurbitales and a new classification of the gourd family (Cucurbitaceae). Taxon 60: 122-138.

Schaefer, H., Heibl, C., and S.S. Renner. 2009. Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events. Proceedings of the Royal Society B 276: 843-851.