Trochomeriopsis Cogn, Monogr. Phan. 3: 661. 1881.
Type: Trochomeriopsis diversifolia Cogn., Boivin 2573, Boivin s.n., Vesco s.n. (P, syntypes), Madagascar.
Perennial climber or trailer with herbaceous and basally woody shoots, thick rootstock and dioecious sex system. The leaves are simple, petiolate, with entire, 5-lobed or 3-5-foliolate blade. The tendrils are simple. The flowers are medium-sized, male flowers are produced in panicles, the female flowers solitary, in pairs or racemes. The receptacle tube is elongate with five small sepals. The five petals are sublinear, 2-4 cm long, yellowish-green. The three stamens are sessile, inserted at the mouth of the tube on very short filaments. Two anthers are bithecous, one monothecous with straight thecae. The pollen is tricolporate, reticulate, small (polar axis c. 37 µm, equatorial axis c. 33 µm, (Keraudren 1968)). The ovary is subcylindrical with three placentae, short style, and three stigmata. The fruit is a cylindrical, smooth, fleshy berry, to 12 cm long and 3.5 cm across, ripening red, tinged with yellow. The 20-30 seeds are triangular, to 8 mm long, with red arilloid. The pale brown or blackish testa is finely sculptured. The chromosome number is n = 12, with diploid, triploid and tetraploid individuals (Keraudren 1968).
The only species, Trochomeriopsis diversifolia, grows on sand dunes or in dry forest and Euphorbia bushland in Madagascar.
Trochomeriopsis is sister to Seyrigia, both in tribe Coninandreae, and split from the latter about 15 million years ago (Schaefer et al. 2009, Schaefer & Renner 2011).
Trochomeriopsis diversifolia Cogn., Monogr. Phan. 3: 661. 1881.
Keraudren, M. 1968. Recherches sur les cucurbitacées de Madagascar. Mémoires du Muséum National d’Histoire Naturelle. Nouvelle Série. Série B, Botanique 16: 122-330.
Khunwasi, C. 1998. Palynology of the Cucurbitaceae. Doctoral Dissertation Naturwiss. Fak., University of Innsbruck.
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.