Thladiantha Bunge
Thladiantha Bunge, Enum. Pl. China Bor. 29. 1833.
Type: Thladiantha dubia Bunge, A.A. Bunge s.n. (P), P. R. China, Hebei, near Beijing.

Perennial climbers or creepers with several meters long herbaceous shoots, tuberous roots, and dioecious sex system. The leaves are simple, petiolate, with entire or rarely pedately 3-7-foliolate blade, the base cordate. The tendrils are simple or bifid. The flowers are medium-sized, yellow, and pollinated by specialized oil bees of the genus Ctenoplectra (Vogel 1990). Male flowers are produced in cymes or racemes (rarely solitary), the female flowers appear mostly solitary or less often in groups of 2-3. The receptacle-tube is shortly campanulate or cup-shaped with five linear, lanceolate, ovate-lanceolate or oblong sepals. The corolla is campanulate with five yellow, entire, oblong, broadly ovate or obovate petals covered with small oil-producing glandular hairs in the lower half of the inner surface. The five stamens are inserted near the mouth of the tube on short, free filaments, usually four in pairs and one single. The anthers are all monothecous with straight thecae, containing medium-sized, tricolporate, reticulate pollen (polar axis 52-79 µm, equatorial axis 64-71 µm, (Khunwasi 1998)). The ovary is ovate, oblong or fusiform, smooth or verrucous with many horizontal ovules, trifid style and three bilobed, reniform stigmata. The fruit is fleshy, indehiscent, smooth or verrucous, ribbed or not ribbed with numerous, horizontal seeds. The testa is brown or blackish, smooth, without distinct margin. The chromosome number is n = 9 (Li et al., 1993).

The 30 species grow in montane forest and bushland, tropical rainforest, riverine forest, on disturbed and cultivated ground in China, Taiwan, Tibet, India, Korea, Japan, Thailand, Vietnam, Indonesia, Philippines, New Guinea. One species, T. dubia, is naturalized and locally weedy in Europe and North America.

The genus Thladiantha is sister group to Baijiania, from which it split about 45 million years ago (Schaefer et al. 2009). Both genera form the tribe Thladiantheae (Schaefer & Renner 2011).

Literature

De Wilde, W. J. J. O. and B. E. E. Duyfjes. 2006. The subtribe Thladianthinae (Cucurbitaceae) in Indochina and Malesia. Blumea 51: 493-518.

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.

Vogel, S. 1990 Ölblumen und ölsammelnde Bienen: dritte Folge. Momordica, Thladiantha und die Ctenoplectridae. Tropische und Subtropische Pflanzenwelt 73: 1-186.