Solanum species of eastern and northern Australia


A. R. Bean

Solanum discolor

Habit. Erect, rhizomatous perennial shrub, 0.5–2 m high.

Branchlets. Branchlets yellow or brown. Branchlet prickles absent or present, 0–10 per decimetre, straight, acicular, 2–6 mm long, 10–16 times longer than wide, glabrous. Branchlet hairs stellate. Branchlet stellae very dense, 0.25–0.4 mm diameter, stalks 0–0.1 mm long. Branchlet stellae lateral rays 7–8, porrect. Branchlet stellae central ray 0.2–0.8 times as long as laterals, not gland-tipped, rigid.

Leaves. Leaves lanceolate or elliptical or ovate, entire or shallowly lobed throughout. Leaf lobes 0 on each side or 3–6 on each side, obtuse, lobing index 1–1.3. Leaves 7–10 cm long, 1.6–4.5 cm wide, 2.3–4.3 times longer than broad. Leaf apex acute or acuminate, base cuneate. Leaf oblique part 0–3 mm long, obliqueness index 0–4 percent. Petioles 0.4–0.9 cm long, 4–10% length of lamina, prickles absent.

Upper leaf surface. Upper leaf surface green. Upper leaf surface prickles absent or present on midvein only or present on midvein and lateral veins, 0–7, straight, acicular, 3–5 mm long. Upper leaf surface stellate hairs absent or confined to midrib, hair density absent from surface. Upper leaf surface simple hairs absent. Upper leaf surface Type 2 hairs absent.

Lower leaf surface. Lower leaf surface white, grey or yellowish. Lower leaf surface prickles absent. Lower leaf surface stellate hair density very dense. Lower leaf surface stellae c. 0.05 mm apart, 0.3–0.5 mm diameter, stalks 0–0.1 mm long. Lower leaf surface stellae lateral rays 8–9, porrect. Lower leaf surface stellae central ray 0.1–0.5 times as long as laterals, not gland-tipped. Lower leaf surface simple hairs absent. Lower leaf surface Type 2 hairs absent.

Inflorescence. Inflorescence leaf-opposed or supra-axillary, cymose (pseudo-racemose). Inflorescence common peduncle absent or present, 0–2 mm long. Inflorescence rachis prickles absent. Inflorescence 7–20-flowered, with one bisexual flower, the rest male or some bisexual and some male flowers. Flowers 5-merous. Pedicels at anthesis 2–9 mm long, same thickness throughout, 0.2–0.4 mm thick at mid-point, prickles absent. Calyx tube at anthesis 0.5–1.5 mm long. Calyx lobes at anthesis deltate, 0.5–2 mm long. Calyx prickles at anthesis absent. Calyx stellae dense to very dense, white, 0.25–0.4 mm across, stalks 0 mm long, lateral rays 6–8. Calyx stellae central ray 0.5–1 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla mauve, 3–7 mm long, deeply lobed, inner surface glabrous. Anthers 2.5–4 mm long. Ovary glabrous.

Fruits. Fruiting calyx lobes less than half length of mature fruit, prickles absent. Mature fruits 1–2 per inflorescence, globular, 10–14 mm diameter, red, 1-locular (septum absent or incomplete). Mature fruits placenta not apparent. Mature fruits interior juicy, succulent, pericarp 0.4–0.5 mm thick. Pedicels at fruiting stage 13–18 mm long, 0.5–0.8 mm thick at mid-point. Seeds pale yellow, 2.6–3.6 mm long.

Distribution and habitat. Queensland. Qld: Cook. Semi-deciduous vine forest on sand, laterite or granite.

Miscellaneous. Subg. Leptostemonum. Data source: specimens.

Cite this publication as: ‘Bean, A.R. 2012 onwards. Solanum species of eastern and northern Australia. Version: 29th June 2013.’.