Synonymy

Lycianthes rantonnetii (Carrière) Bitter, Abh. Naturwiss. Vereine Bremen 24: 332 (1920). Solanum rantonnetii Carrière, Rev. Hort. 135, t.32 (1859); originally as rantonnei.

T: "Il y a environs dix and qu'un officier de marine, ayant rapporté des graines qu'il avait recuilles aux environs de la Plata, les donna à un horticulteur de Toulon ..." Quoted from Australian Plant Name Index where there is also a discussion of the correct spelling of the epithet. This is also discussed on the Solanaceae Source where the explanation is given for why "rantonnetii" is the correct form of the name honouring Rantonnet.

See also: Julian M. H. Shaw (2004). Proposal to conserve the name Solanum rantonnetii (Solanaceae) with that spelling. Taxon 53: 1077-1078.

Description

Arching or sprawling shrub 2-3 m high, green; glabrous except for simple or branched hairs on underside of leaves; prickles absent. Stems somewhat angular, sparsely striate.

Leaves sometimes geminate, elliptic; lamina to 10 cm long, 5 cm wide, concolorous, entire, base cuneate, apex acute or acuminate; petiole 0.5-1.5 cm long, winged in upper part by extension of lamina base.

Inflorescence axillary, sub-umbellate cluster of 2-5 somewhat zygomorphic flowers; pedicels 15-25 mm long. Calyx 4–5 mm long; lobes 2 mm long, linear, 5 well-developed with secondary lobe sometimes developing between to give 10-lobed effect. Corolla rotate, 20–30 mm diam., bright blue, upper 3 lobes with yellow patch at base. Anthers unequal, upper pair slightly smaller, c. 3 mm long, oblong.

Berry (not seen) reported as sub-globose-ellipsoid with cordate base, 27–30 mm long, yellow. Seed c. 2.5 mm long, dark brown. Stone cells numerous, c. 1.5 mm wide. n=24.

Distribution and ecology

South American native cultivated as an ornamental in Australian gardens. Sparingly naturalised in SA, and according to the map generated on the AVH and reproduced here, in WA, but it is not recorded in the WA Census.

Common name

Blue Potato Bush, Paraguay nightshade, Royal robe

Relationships

Sometimes treated in the genus Solanum, but placed in Lycianthes by its axillary flowers, these without a peduncle when more than one, and because of the non-lobed or 5-10-toothed calyx. DNA studies support the distinction of Lycianthes from Solanum and place it closest to Capsicum; see for example Olmstead et al. 1999 or the discussion of phylogeny on the Solanaceae Source pages

Reference: Olmstead, R. G., J. A. Sweere, R. E. Spangler, L. Bohs, and J. D. Palmer (1999) Phylogeny and provisional classification of the Solanaceae based on chloroplast DNA. M. Nee, D. E. Symon, R. N. Lester, & J. P. Jessop (eds.), Solanaceae IV: advances in biology and utilization. (Royal Botanic Gardens, Kew). pp. 111-137. Available at http://depts.washington.edu/phylo/OlmsteadPubs/Solanaceae_IV.pdf

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Notes

Olmstead, R. G., J. A. Sweere, R. E. Spangler, L. Bohs, and J. D. Palmer (1999) Phylogeny and provisional classification of the Solanaceae based on chloroplast DNA. M. Nee, D. E. Symon, R. N. Lester, & J. P. Jessop (eds.), Solanaceae IV: advances in biology and utilization. (Royal Botanic Gardens, Kew). pp. 111-137. Available at http://depts.washington.edu/phylo/OlmsteadPubs/Solanaceae_IV.pdf

Fruits rarely develop in the ornamental material grown in Australia.

Derivation of epithet

Named for M. Victor Rantonnet, 19th century French horticulturist of Hyères, a town on the Mediterranean coast of southern France.

From the web

Information on the web can be found under various combinations and spellings. Try Solanum rantonnetii/rantonnei or Lycianthes rantonnetii/rantonnei.

The United States Department of Agriculture Germplasm Resources Information Network (GRIN) has numerous links for this species.

Images of S. rantonnetii can be seen on the Plants of Hawaii site, the Virtual Botanic Garden site at http://www.virboga.de/Lycianthes_rantonnetii.htm at

http://biopl-a-181.plantbio.cornell.edu/taxpage/0/0/79/binomial/Lycianthes%20rantonnetii.htm and at

http://www.plantsystematics.org/

There is limited information on the Solanaceae Source site but there is an explanation for the correct spelling of the epithet.