Solanum cunninghamii Benth., Fl. Austral. 4: 465 (1868)

T: Cygnet Bay, NW Coast, W.A., A. Cunningham 134; lecto: K; iso: BM, fide D.E. Symon, J. Adelaide Bot. Gard. 4: 291-292 (1981); NW Coast, Bynoe s.n.; syn: K; Glenelg district, Martin s.n.; syn: MEL. Images of isolectotype material can be seen on the Solanaceae Source site.

Erect, clonal shrub to 2m, male or female, rusty-green, densely pubescent with stellate hairs; prickles 2-5 mm long, abundant on calyx-tube of bisexual flower, usually scattered on stems.  

Leaves lanceolate-elliptic; lamina 3-7 cm long, 1-1.5 cm wide, sometimes larger, discolorous, entire; petiole 5-10 mm long.  

Male plant: inflorescence up to 50-flowered; peduncle 20-30 mm long; rachis 10-15 cm long, pedicels 2-4 mm long; calyx 4-6 mm long, the lobes triangular, 2-4 mm long; corolla shallowly campanulate-rotate, 25-30 mm diam., purple-blue; anthers 3-4 mm long. Female plant: flowers solitary; pedicels 5-15 mm long, lengthened in fruit; calyx 9-14, sometimes to 20, mm long, enlarged in fruit, the lobes more or less linear, 5-7(-10) mm long; corolla rotate, 20-30 mm diam., purple; anthers 3-4 mm long.  

Berry globular or depressed globular, 20 mm diam.; colour unknown; fruiting pedicels 15-20 mm long; fruiting calyx 25-30 mm diam. Seeds 2 mm long, dark brown. n=12.

All of the dioecious members of the Dioicum group of subgen. Leptostemonum exhibit functional dioecy i.e. male flowers are borne on separate plants from what appear to be plants with bisexual or hermaphrodite flowers; while these bisexual flowers do produce pollen, it is inaperturate and does not germinate, making the flowers effectively female (Knapp et al.,1998).

Initial molecular studies by Martine et al. (2006) suggested that the two functionally dioecious species from Kakadu, S. asymmetriphyllum and the newly described S. sejunctum, formed a separate clade and had arisen separately from the other dioecious members of the Dioicum group, S. cunninghamii, S. cataphractum , S. dioicum, S. petraeum, S. carduiforme, S. tudununggae, S. vansittartense  and S. leopoldense. T his initial DNA analysis involved sequencing of the ITS region of nuclear rDNA.

However further molecular analysis involving the trnK-matK gene region indicated that all of the functionally dioecious species form a single clade arising from the andromononoecious species of the group (Martine et al., 2009).

References: S.Knapp, V.Persson & S.Blackmore (1998). Pollen morphology and functional dioecy in Solanum (Solanaceae). Pl. Syst. Evol. 210:113-139.; Martine, C.T., D. Vanderpool, G.J. Anderson, and D.H. Les (2006). Phylogenetic relationships of andromonoecious and dioecious Australian species of Solanum subgenus Leptostemonum section Melongena: Inferences from ITS sequence data. Systematic Botany 31: 410-420; Martine, C.T., G.J. Anderson & D.H. Les (2006). Gender-bending aubergines; molecular phylogenetics of cryptically dioecious Solanum in Australia. Australian Systematic Botany 22: 107-120.