Solanum species of eastern and northern Australia


A. R. Bean

Solanum melanospermum

Habit. Erect, rhizomatous perennial shrub, 0.7–1.2 m high.

Branchlets. Branchlets rusty. Branchlet prickles 15–35 per decimetre, straight, broad-based, 1.5–8 mm long, 5–12 times longer than wide, with dense stellate hairs on lower part (most of prickle bearing hairs). Branchlet hairs stellate. Branchlet stellae sparse to moderate, 0.7–1 mm diameter, stalks 0–0.4 mm long. Branchlet stellae lateral rays 4–6, porrect. Branchlet stellae central ray 0.5–1.2 times as long as laterals, not gland-tipped. Branchlet Type 2 hairs absent.

Leaves. Leaves ovate or broadly ovate, shallowly lobed throughout or deeply lobed throughout. Leaf lobes 3–4 on each side, obtuse, lobing index 1.6–3.3. Leaves 4.5–8.5 cm long, 3.5–7 cm wide, 1.2–1.6 times longer than broad. Leaf apex obtuse or acute, base obtuse. Leaf oblique part 7–10 mm long, obliqueness index 14–16 percent. Petioles 1.1–3.4 cm long, 22–40% length of lamina, prickles absent or present.

Upper leaf surface. Upper leaf surface green. Upper leaf surface prickles absent. Upper leaf surface stellate hairs distributed throughout, protostellae absent, hair density moderate density or dense. Upper leaf surface stellae 0.2–0.4 mm apart, 0.45–0.7 mm across, stalks 0–0.1 mm long. Upper leaf surface stellae lateral rays 5–8, porrect. Upper leaf surface stellae central ray 0.6–1.2 times as long as laterals, not gland-tipped. Upper leaf surface simple hairs absent. Upper leaf surface Type 2 hairs absent.

Lower leaf surface. Lower leaf surface yellowish or rusty. Lower leaf surface prickles absent or present on midvein only or present on midvein and lateral veins, 0–15, straight, broad-based. Lower leaf surface stellate hair density dense. Lower leaf surface stellae 0.15–0.25 mm apart, 0.7–0.9 mm diameter, stalks 0–0.2 mm long. Lower leaf surface stellae lateral rays 7–8, porrect. Lower leaf surface stellae central ray 0.8–1.2 times as long as laterals, not gland-tipped. Lower leaf surface simple hairs absent. Lower leaf surface Type 2 hairs absent.

Inflorescence. Inflorescence supra-axillary, cymose (pseudo-racemose). Inflorescence common peduncle absent. Inflorescence rachis prickles present. Inflorescence 5–14-flowered, with one bisexual flower, the rest male. Flowers 5-merous, markedly dimorphic, with larger pricklier basal flower(s). Pedicels at anthesis 8–30 mm long, same thickness throughout, 0.3–0.7 mm thick at mid-point, prickles absent or present. Pedicels with indument prominent on distal end and glabrous on proximal end. Calyx prickles on basal bisexual flowers 50–70, 2–9 mm long. Calyx prickles on distal male flowers 0–8, 1–3 mm long. Calyx tube at anthesis 2–4 mm long. Calyx lobes at anthesis attenuate, 1.5–8 mm long. Calyx stellae very dense, yellow or brown or rusty, 0.5–0.9 mm across, stalks 0–0.2 mm long, lateral rays 6–8. Calyx stellae central ray 0.6–1.2 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla purple, 10–22 mm long, rotate, inner surface sparsely stellate-hairy. Anthers 5.4–7.3 mm long. Filaments 0.5–1.7 mm long. Ovary glabrous. Functional style 18 mm long, protruding between anthers, glabrous.

Fruits. Fruiting calyx lobes more than half length of mature fruit, prickles 4–12 mm long. Mature fruits 1 per inflorescence, ellipsoidal or ovoid, 20–27 mm diameter, yellow. Pedicels at fruiting stage 25–30 mm long, 1.5–1.7 mm thick at mid-point. Seeds black, 3.7–4.3 mm long.

Distribution and habitat. Northern Territory.

Miscellaneous. Subg. Leptostemonum. Data source: specimens, Symon (1981).

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