Solanum tetrathecum
n = ploidy missing =24 voucher: Randell 039 (ADW) (Randell & Symon 1976)
Solanum tetrathecum is endemic to Queensland. It is known from two separate areas: the main area is on the western Darling Downs from Allies Creek to Westmar; the other is around Kingaroy and Yarraman. It usually inhabits heavy clays soils in Brigalow-Belah forest, but also grows on the margins of notophyll rainforest, in Eucalyptus populnea woodland or (rarely) on stony ironbark ridges.
Solanum tetrathecum is a typical member of Solanum subgenus Leptostemonum. It is placed into the S. macoorai group (Group 27B) by Bean (2004) on morphological grounds; its phylogenetic position has not been investigated using molecular data.
Symon, D.E. 1981. A revision of Solanum in Australia.
J. Adelaide Bot. Gard. 4: 1-367.
Bean, A.R. 2004. The taxonomy and ecology of Solanum subg. Leptostemonum (Dunal) Bitter (Solanaceae) in Queensland and far north-eastern New South Wales.
Austrobaileya 6 (4): 639-816.
Solanum jucundum is closely related to S. tetrathecum, but S. jucundum differs by the moderate to very dense indumentum of the upper leaf surface, perennial habit and greater height (up to 1.8 m high), the acute leaf apex, the rostrate to attenuate calyx lobes, the calyx stellae with stalks 0.1-0.4 mm long (0-0.1 mm for S. tetrathecum) and the style bearing very short, gland-tipped hairs only (very short, gland-tipped hairs and stellate hairs for S. tetrathecum). The distributions of S. jucundum and S. tetrathecum overlap considerably, especially around Glenmorgan, Hannaford and Westmar, but they never grow together and there is no intergradation between them.
Conservation status: Widespread. Not considered at risk.