Dactyliandra.

Dactyliandra (Hook.f.) Hook.f.
Dactyliandra (Hook.f.) Hook.f., Fl. Trop. Afr. 2: 557. 1871.
Type: Dactyliandra welwitschii (Hook.f.) Hook.f.; F.M.J. Welwitsch 832 (holotype: LISU; isotypes: BM), Angola, Mossamedes, 1859.

Herbaceous climber or trailer with perennial rootstock and monoecious sex system. The leaves are simple, the blade unlobed to palmately 5-lobed, petiolate with stipuliform bract at petiole base. The tendrils are simple. The flowers are small, white. The male flowers are produced in pedunculate racemes, the female flowers are mostly solitary. The receptacle-tube is campanulate with five triangular, small sepals. The corolla is rotate with five free petals, ± 2 mm long. The three stamens are inserted near the base of the tube on free filaments. Two anthers are bithecous, one is monothecous. The thecae are duplicate and contain tricolporate, striate-reticulate, medium-sized pollen (polar axis 59-73 µm, equatorial axis 62-65 µm (Khunwasi 1998)). The ovary is ovoid with three placentae and many, horizontal ovules. The single style holds a trilobed stigma. The fruit is a globose berry, ripening pink. The few seeds are compressed, oblong to pear-shaped, ± angular with a smooth, thick testa.

The only species, D. welwitschii, is restricted to the Namib desert of Namibia and Angola and an isolated population in the Thar desert at the border of India and Pakistan (Lindner et al. 2017).

Phylogenetically, Dactyliandra is sister to Trochomeria and the two are sister clade to Blastania (Schaefer et al., 2009; Lindner et al., 2017).

Accepted species

Dactyliandra welwitschii (Hook.f.) Hook.f., Fl. Trop. Afr. 2: 557. 1871.

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.

Maheshwari, J.K., and V.S. Sharma. 1969 [1972]. Some interesting plants from Upper Gangetic Plain. Bull. Bot. Surv. India 11: 454-456.

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.

Singh, A.K. 1977. Cytogenetics of semi-arid plants: 4. Cytology of Dactyliandra welwitschii Hook. f. of Cucurbitaceae. Sci. Cult. Calcutta, India 43: 141.