Austrobryonia H. Schaef.
Austrobryonia H. Schaef. in Schaefer, H., Telford, I.R.H. and S. S. Renner. Syst. Bot. 33: 125-132. 2008.
Type: Austrobryonia micrantha (F. Muell.) I. Telford; basionym: Cucurbita micrantha F. Muell., Trans. Philos. Soc. Victoria 1: 17. 1854; F. von Mueller s.n. (holotype, MEL; isotype BR), Australia, Murray River, Victoria.
Perennial or annual, trailing herbs with woody rootstock and monoecious sex system. The leaves are simple, petiolate, with a more or less ovate, unlobed or shallowly 3-, 5- or 7-lobed blade. The tendrils are simple. The flowers are solitary or in small fascicles, the receptacle-tube is broadly campanulate. The five sepals are small and narrowly triangular, the five petals are yellow to yellowish-green, ovate. The three stamens are inserted halfway up the tube on short, free filaments. Two anthers are bithecous, one monothecous, the thecae curved with tricolpate-oblate pollen. The ovary is subglobose or ellipsoidal with many, horizontal ovules. The style is very short or absent, the stigma 2- or 5-lobed, with capitate or linear, papillose lobes. The fruit is a globose or ellipsoidal berry, 10-35 mm long, ripening green to yellow, with few to several, ovate, compressed seeds. The testa is smooth, pale, sometimes with thickened margins.
The four species grow on clay soils of river flood plains, waterhole and dam margins and swales in dune fields, grasslands on cracking clay, grassy woodlands on red earth. All species are endemic in dry regions of Central and Western Australia.
Phylogenetically, Austrobryonia groups with the Eurasian/Mediterranean genera Bryonia and Ecballium (Schaefer & Renner 2011).
Austrobryonia argillicola I. Telford, Syst. Bot. 33: 128. 2008.
Austrobryonia centralis I. Telford, Syst. Bot. 33: 130. 2008.
Austrobryonia micrantha (F. Muell.) I. Telford, Syst. Bot. 33: 126. 2008.
Austrobryonia pilbarensis I. Telford, Syst. Bot. 33: 129. 2008.
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., Telford, I. R. H. and S. S. Renner. 2008. Austrobryonia (Cucurbitaceae), a new Australian endemic genus, is the closest living relative to the Eurasian and Mediterranean Bryonia and Ecballium. Syst. Bot. 33: 125-132.