Streptosolen Miers

Solanaceae, Jennifer M Edmonds. Oliganthes, Melongena & Monodolichopus, Maria S. Vorontsova & Sandra Knapp. Flora of Tropical East Africa. 2012

Morphology General

Evergreen shrubs, all vegetative and floral parts conspicuously pubescent with eglandular and glandular-headed hairs usually intermixed with stalked glands

Morphology Leaves

Leaves alternate; petioles scabrid. Inflorescences terminal subcorymbose leafopposed cymes, usually many-flowered. Calyx tubular or campanulate, somewhat zygomorphic with four or five sometimes unequal teeth; netveined, scabrid externally

Morphology Reproductive morphology Flowers Corolla

Corolla infundibuliform, tubular or trumpet-shaped, basal tube spirally twisted and tapering towards the calyx, terminating in five lobes which partially reflexed together with apical part of the tube

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, didynamous, usually included; filaments unequal, two lower posterior fused to basal quarter of corolla tube and two upper lateral fused to apical quarter of the tube, all densely pilose and becoming thicker at point of fusion; anthers unequal, lateral smaller and glabrous, posterior larger and pilose, elongate, dorsifixed

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary bilocular, ovules numerous; disc annular, smooth; style filiform below, becoming thicker and rugose for upper half, curved beneath the stigma, glabrous, usually included; stigma broadly dilated, somewhat sagittate, bilobed

Morphology Reproductive morphology Fruits

Fruit globose or ovoid dehiscent bivalvate capsule, valves often bifid, usually wholly enclosed by accrescent persistent calyx

Morphology Reproductive morphology Seeds

Seeds numerous, cuboidal to obovoid, reticulate.

Note

Although Mabberley (in Mabberley’s Plant Book, 3rd ed.: 826 (2008)) considers Streptosolen to be a synonym of Browallia, the two genera have been retained separately here, as in Hunziker (2001) and all other recent African treatments of the family. Hunziker used habit and a number of floral characters together with pollination vectors to differentiate these genera; they are also reported to differ in their basic chromosome number. Molecular work places these two genera firmly within the same clade (cf. Olmstead et al. in Taxon 57: 1167 (2008)) but there is as yet no molecular data on their relationship at the species level. If these two genera prove to be unequivocably conspecific, Streptosolen would be synonymised with Browallia with the two species Browallia jamesonii and B. americana occurring in the FTEA area. Streptosolen is characterised by colourful tubular orange-red flowers, and is often grown as an ornamental.