Synonymy

Solanum orbiculatum Dunal ex Poiret, Encycl. Suppl. 3: 762 (1814) subsp. orbiculatum

T: New Holland: ora occident. Voy du Capitaine Baudin, W.A.,1801, collector unknown; lecto: P; isolecto: K, MPU.

Solanum orbiculatum was originally lectotypified, Symon J. Adelaide Bot. Gard. 4: 156 (1981) by a specimen collected at Shark Bay by Gaudichaud now at Paris. Dr Alex George (pers. comm. 1999) has pointed out that this is in error as the specimen was collected too late to have been used by Dunal.

The new proposed lectotype is cited above, but note that there are at least 2 specimens attributed to Baudin cited in the Sonnerat database for P and others are shown on the Solanaceae Source site in BM which may also be attributable to Baudin.

Description

Erect or rounded, clonal shrub to 1.5 m, silvery-green or rusty-green, rarely greyish-green, all parts densely pubescent with stellate hairs; prickles absent, if present 5–15 mm long, sparsely scattered on stems.

Leaves usually orbicular, concolorous; lamina 15–30 mm long, sometimes larger, entire; petiole 5–20 mm long.

Inflorescence 1–4–flowered; peduncle to 10 mm long; rachis 3–5 mm long, pedicels 5–12 mm long. Calyx 4–7 mm long; lobes broadly triangular, 1–2 mm long, slightly elongated in fruit. Corolla stellate, 20–25 mm diam., violet. Anthers 5–7 mm long.

Berry globular, 10–15 mm diam., yellow-ivory, drying dark brown. Seeds 2–3 mm long, pale brown. n=12.

Distribution and ecology

Widespread in central W.A. on coastal dunes and gravelly and sandy inland plains, extending to southern N.T. and western S.A. where found on low, red sand dunes.

Relationships

Distinct from subsp. macrophyllum by its usually circular leaves of 1.5-3 cm diameter, its dense pubescence and silvery-green or rusty-green overall appearance.

Closely related to S. nummularium S. Moore; distinguished by the more open habit, larger leaves and generally pale tomentum.

Considered by Bean (2004) to be a member of the S. esuriale group of subgen. Leptostemonum.

Notes

First collected from Western Australia by William Dampier and one of 24 Dampier specimens still existing in the University of Oxford herbarium.

Reference: George, AS. (1999). William Dampier in New Holland: Australia's first natural historian. (Blooming Books: Hawthorn, Vic).

Fresh fruit reputedly eaten by central Australian Aborigines (see P.K. Latz (1995). Bushfires & Bushtucker. Aboriginal Plant Use in Central Australia. IAD Press, Alice Springs).

Germination studies for mine regeneration or the native food industry indicated that germination of seed of this species is promoted with gibberellic acid, smoke water or the smoke isolate, karrikinolide.

Reference: Commander LE, Merritt DJ, Rokich DP, Flematti GR & Dixon KW (2008). Seed germination of Solanum spp. (Solanaceae) for use in rehabilitation and commercial industries . Australian Journal of Botany 56, 333–341.

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Plant status, if any

This taxon does not have any status in WA and has a conservation status as a plant of least concern in theNorthern Territory – see www.nt.gov.au/nreta/wildlife/animals/native/pdf/plants_lcs-z.pdf

From the web

Further information and images can be found on the FloraBase site. Images not identified to subspecies can also be seen on this site at http://florabase.calm.wa.gov.au/browse/profile/7026

A fact sheet for the species can be downloaded from the SA eFlora site.

As a target for the Millenium Seed Bank, with image - see www.kew.org/msbp/where/Aus_NT.htm

Limited information for this species can be found on the Solanaceae Source site.