Trochomeria Hook.f.
Trochomeria Hook.f. in Benth. & Hook., Gen. Pl. 1: 822. 1867.

Type: Trochomeria debilis (Sond.) Hook.f., Fl. Trop. Afr. 2: 525. 1871; basionym: Zehneria debilis Sond., C.L.P. Zeyher 577 (GDC, P, S, TCD, syntypes), South Africa, Beaufort, Rhinosterkop.

Heterosicyos Welw. ex Benth. & Hook., Gen. Pl. 1: 822. 1867.

Perennial climbers or trailers with up to 2.5 m long herbaceous shoots or erect herb without tendrils, with tuberous rootstock and dioecious sex system. The leaves are simple, subsessile to petiolate, often with ciliate stipuliform bract at petiole base and linear, elliptic, ovate-cordate, or sagittate, 3-lobed or palmately 3-5-lobed blade. The tendrils are simple or absent. The flowers are medium-sized, often on leafless stems, opening in the evening (Zimmermann 1922). The male flowers are produced in pedunculate clusters (rarely simple), the female flowers stand solitary (rarely paired), exceptionally flowers can be bisexual (Jeffrey 1967). The receptacle-tube is cylindrical, elongated with five minute sepals. The corolla is rotate with five free petals, up to 10 mm long, triangular to linear, spreading, greenish or lemon-yellow sometimes with yellow papillae. The three stamens are inserted in the upper half of the tube on free filaments. Two anthers are bithecous, one monothecous, all united into an oblong head. The triplicate thecae contain tricolporate, perforate or reticulate, medium-sized pollen (polar axis 62-83 µm, equatorial axis 62-83 µm, (Khunwasi 1998)). The ovary is ovoid to subglobose, rostrate with horizontal ovules and trilobed stigma. The fruit is a fleshy, ellipsoid to subglobose, beaked, small to medium-sized berry, indehiscent, ripening scarlet. The few seeds are subglobose, ovoid or ellipsoid, and tumid. The testa is smooth, hard, whitish (rarely pitted).

The eleven species grow in deciduous forest and dry bushland of tropical and subtropical Africa.

Trochomeria is sister to Dactyliandra (Lindner et al. 2017), from which it split about seven million years ago (Schaefer et al. 2009). Both genera are placed in tribe Benincaseae (Schaefer & Renner 2011).

Literature

Khunwasi, C. 1998. Palynology of the Cucurbitaceae. Doctoral Dissertation Naturwiss. Fak., University of Innsbruck.

Lindner, K., Hu, Y., Pandey, A.K. and H. Schaefer. 2017. The Namib-Thar desert disjunction in Dactyliandra (Cucurbitaceae) is the result of a recent introduction to India. Systematic Botany 42:63-72.

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.