Psiguria Neck. ex Arn.
Psiguria Neck. ex Arn., J. Bot. (Hooker) 3: 274-275. 1841.
Type: Psiguria pedata (L.) R.A. Howard; basionym: Cucumis pedatus L., Plumier in Burman, Pl. Amer. 13, t. 23. 1755, lectotype designated by Howard, J. Arnold Arbor. 54: 441. 1973.
Anguria Jacq., Enum. Syst. Pl. 9, 31. 1760 (nom. illegit.).
Perennial climbers with herbaceous or woody shoots reaching up to 10 m or more in length. The plants appear dioecious, but most species seem to be monoecious, with plants first male, then female (Condon & Gilbert 1988). The leaves are petiolate, simple, with entire and palmately 3-5-lobed or 3-foliolate blades. The tendrils are simple. The flowers are small to large, visited by hummingbirds and Heliconius butterflies (Murawski et al. 1986). Male flowers are produced in racemes or axillary spikes, female flowers stand solitary or in groups of 2-5. The receptacle-tube is urceolate to cylindrical, with five small, triangular, green sepals. The five petals are broad, spreading, red, orange, or pink. The two stamens are inserted halfway up the tube on free filaments. The anthers are bithecous with duplicate or rarely straight thecae. The pollen is produced in monads or tetrads (152-185 µm in diameter), the monads are medium-sized to large (polar axis 77-80 µm, equatorial axis 98-126 µm), 3-6-porate, verrucate, perforate or psilate (Khunwasi 1998). The ovary is oblong, smooth with two placentae, many horizontal ovules and two stigmata. The fruits are fleshy, ellipsoid to oblong, smooth, indehiscent, 3-8 cm long and 2-3 cm across, ripening yellowish-green or black, sometimes striped. The many seeds are up to 11 mm long, oblong-elliptic, compressed, with smooth, grey testa.
The six species grow in tropical forest of Central America and tropical South America.
Phylogenetically, the genus is close to the genera Gurania and Helmontia, all in tribe Coniandreae (Schaefer et al. 2009, Schaefer & Renner 2011).
Psiguria pedata (L.) R.A. Howard, J. Arnold Arbor. 54: 441. 1973.
Psiguria racemosa C. Jeffrey, Kew Bull. 33: 354. 1978.
Psiguria ternata (M. Roem.) C. Jeffrey, Kew Bull. 33: 354. 1978.
Psiguria triphylla (Miq.) C. Jeffrey, Kew Bull. 33: 353. 1978.
Psiguria umbrosa (Kunth) C. Jeffrey, Kew Bull. 33: 353. 1978.
Psiguria warscewiczii (Hook.f.) Wunderlin, Phytologia 38: 219. 1978.
Condon, M.A. and L.E. Gilbert. 1988. Sex expression of Gurania and Psiguria (Cucurbitaceae): Neotropical vines that change sex. Am. J. Bot. 75: 875-884.
Jeffrey, C., 1962. The application of the generic names Anguria and Elaterium (Cucurbitaceae). Kew Bull. 16: 197-198.
Murawski, D.A. and L.E. Gilbert. 1986. Pollen flow in Psiguria warscewiczii: a comparison of Heliconius butterflies and hummingbirds. Oecologia 68: 161-167.
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.
Steele, P.R., Friar, L.M., Gilbert, L.E. and R.K. Jansen. 2010. Molecular systematics of the neotropical genus Psiguria (Cucurbitaceae): Implications for phylogeny and species identification. Am. J. Bot. 97: 156-173.