Solanum species of eastern and northern Australia

DELTA Home

A. R. Bean

Solanum oligacanthum

Habit. Erect, herbaceous resprouter or rhizomatous perennial shrub, 0.2–0.6 m high.

Branchlets. Branchlets white or grey. Branchlet prickles absent or present, 0–30 per decimetre, straight, acicular, 0.5–13 mm long, 8–11 times longer than wide, with scattered stellate hairs on lower half. Branchlet hairs stellate. Branchlet stellae very dense, 0.2–0.4 mm diameter, stalks 0–0.1 mm long. Branchlet stellae lateral rays 13–15, porrect or multiradiate. Branchlet stellae central ray absent or present, 0–0.7 times as long as laterals, not gland-tipped, thready. Branchlet Type 2 hairs absent.

Leaves. Leaves broadly ovate or orbicular, entire. Leaves 1–2.5 cm long, 0.9–2.8 cm wide, 0.8–1.4 times longer than broad. Leaf apex obtuse, base obtuse or cordate. Leaf oblique part 0–1 mm long, obliqueness index 0–6 percent. Petioles 0.1–0.3 cm long, 6–18% length of lamina, prickles absent.

Upper leaf surface. Upper leaf surface green or grey-green or grey. Upper leaf surface prickles absent or present on midvein only, 0–2, straight, acicular, 1–7 mm long. Upper leaf surface stellate hairs distributed throughout, protostellae absent, hair density moderate density to dense. Upper leaf surface stellae 0.1–0.25 mm apart, 0.15–0.3 mm across, stalks 0 mm long. Upper leaf surface stellae lateral rays 12–16, porrect or multiradiate. Upper leaf surface stellae central ray 0.1–0.5 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 white, grey. Lower leaf surface prickles absent. Lower leaf surface stellate hair density very dense. Lower leaf surface stellae c. 0.05 mm apart, 0.2–0.35 mm diameter, stalks 0 mm long. Lower leaf surface stellae lateral rays 9–18, porrect or multiradiate. Lower leaf surface stellae central ray 0.3–0.8 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 or present, 0–4 mm long. Inflorescence rachis prickles absent or present. Inflorescence 4–6-flowered. Flowers 5-merous. Pedicels at anthesis 2.5–7 mm long, same thickness throughout, 0.5–0.8 mm thick at mid-point, prickles absent. Calyx tube at anthesis 2–3 mm long. Calyx lobes at anthesis deltate, 2.5–3.5 mm long. Calyx prickles at anthesis absent. Calyx stellae very dense, yellow or white, 0.3–0.4 mm across, stalks 0–0.2 mm long, lateral rays 10–16. Calyx stellae central ray 0.7–1.3 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla purple, 8–11 mm long, rotate, inner surface glabrous. Anthers 3.5–5.5 mm long. Ovary with Type 2 hairs only. Functional style 7–8 mm long, protruding between anthers, with Type 2 hairs only.

Fruits. Fruiting calyx lobes less than half length of mature fruit, prickles absent. Mature fruits 1–6 per inflorescence, globular, 8–11 mm diameter, brown or yellow. Mature fruits interior moist but not juicy. Pedicels at fruiting stage 3–8 mm long, 0.6–0.9 mm thick at mid-point. Seeds black, 3.6–5.3 mm long.

Distribution and habitat. Queensland, New South Wales. Qld: Gregory South, Gregory North. NSW: North Far Western Plains. Shrublands in arid zone.

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. http://delta-intkey.com’.

Contents