Synonymy

Solanum melanospermum F. Muell., Fragm. Phytogr. Austral. 2: 163 (1861)

T: Abel Tasman's River (?= Robinson River), Gulf of Carpentaria, coll. unknown; holo: MEL 12085; iso: K.

Description

Erect shrub to 1.5 m, rusty-green, densely pubescent with stellate hairs; prickles to 7 mm long, abundant on calyx of bisexual flowers and young stems, sparse to absent elsewhere.

Leaves ovate-lanceolate; lamina 4-7 cm long, 1.5-4 cm wide, concolorous, with several shallow lobes towards base; petiole 10-15 mm long. Juvenile leaves ovate, up to 15 cm long, 10 cm wide, lobed to deeply lobed; petiole 4-7 cm long.

Inflorescence of one bisexual flower below cyme of up to 10 male flowers; peduncle absent or very short; rachis to 5 cm long. Bisexual flower: pedicels 2-3 cm long, lengthened in fruit; calyx 10-17 mm long, the lobes linear, 5-7 mm long, enlarged in fruit; corolla broadly stellate to pentagonal, 40-45 mm diam., purple; anthers 7 mm long. Male flowers: pedicels 2 cm long; calyx 5-6 mm long, the lobes triangular, c. 3 mm long; corolla broadly stellate, 30-35 mm diam., purple; anthers c. 6 mm long.

Berry broadly ellipsoid, 2.5 cm long, pale yellow with deeper yellow stripes; fruiting pedicel 3-4 cm long; fruiting calyx lobes 1-2 cm long. Seeds 4 mm long, almost black. n=12.

Distribution and ecology

In Symon (1981) restricted to McArthur and Robinson River area in north-eastern N.T., occurring on river flats in open Eucalypt woodland. A plot of distribution now indicates a much wider distribution in more southern regions of NT. The identification of the specimens concerned needs to be confirmed.

Relationships

An andromonoecious species i.e. one in which there are male flowers and bisexual flowers on the one plant. Often there are many male flowers in an inflorescence with 1(-2) bisexual flowers at their base.

Andromonoecious species of the Dioicum group include S. beaugleholei, S. clarkiae, S. chippendalei, S. diversiflorum, S. eburneum, S. heteropodium, S. melanospermum, S. oedipus and S. phlomoides .

Symon (1981) indicated that S. melanospermum was closely related to S. chippendalei and S. phlomoides, with distinctly separate populations geographically but intergradation in the intervening areas. However DNA ITS studies by Martine et al. (2006) indicated that relationships were with S. clarkiae with these two species forming one of three clades suggested for the andromonoecious species of the Dioicum group.

However further molecular analysis involving the trnK-matK gene region has indicated that all of the Australian andromonoecious species (except for S. campanulatum , S. cinereum and S. stupefactum) form a clade which also includes two African andromonoecious species and the Australian hermaphrodite species S. hoplopetalum (Martine et al., 2009).

References: 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 (2009). Gender-bending aubergines; molecular phylogenetics of cryptically dioecious Solanum in Australia. Australian Systematic Botany 22: 107-120.

Selected specimens

N.T.: MacArthur River Stn, Aug. 1970, I. Mellor (DNA); 32 km NW of Robinson River Homestead, D.E. Symon 5064 (AD: 2 sheets, B, CANB, K, NSW, NT, US).

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Plant status, if any

While once Classified as Risk Code 2K (Briggs & Leigh, Rare or Threatened Australian Plants, 1995) the Northern Territory Government includes S. melanospermum in their list of Least Concern plants - see http://www.nt.gov.au/nreta/wildlife/animals/native/pdf/plants_lcs-z.pdf

From the web

There is presently no information for this species on the Solanaceae Source site.