Solanum species of eastern and northern Australia

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A. R. Bean

Solanum unispinum

Habit. Erect, herbaceous resprouter or rhizomatous perennial shrub, 0.3 m high.

Branchlets. Branchlets mauve to purple or yellow or rusty or brown. Branchlet prickles 9–40 per decimetre, straight, acicular, 3–8 mm long, 12–16 times longer than wide, glabrous. Branchlet stellae very dense, 0.4–0.7 mm diameter, stalks 0–0.1 mm long. Branchlet stellae lateral rays 8–10, porrect. Branchlet stellae central ray 0.4–0.8 times as long as laterals, not gland-tipped.

Leaves. Leaves ovate or broadly ovate, entire. Leaves 2.2–3.5 cm long, 1.4–2.1 cm wide, 1.6–1.7 times longer than broad. Leaf apex obtuse or acute, base obtuse. Leaf oblique part 0–2 mm long, obliqueness index 0–9 percent. Petioles 1.4–2.7 cm long, 58–77% length of lamina, prickles present.

Upper leaf surface. Upper leaf surface grey-green. Upper leaf surface prickles absent. Upper leaf surface stellate hairs distributed throughout, protostellae absent, hair density dense. Upper leaf surface stellae 0.15–0.2 mm apart, 0.4–0.5 mm across, stalks 0–0.1 mm long. Upper leaf surface stellae lateral rays 8. Upper leaf surface stellae central ray 0.6–0.9 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 or present on midvein only, 0–3, straight, acicular. Lower leaf surface stellate hair density dense or very dense. Lower leaf surface stellae 0.05–0.1 mm apart, 0.4–0.55 mm diameter, stalks 0–0.1 mm long. Lower leaf surface stellae lateral rays 8–9, porrect. Lower leaf surface stellae central ray 0.4–1 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 3–10 mm long. Inflorescence rachis prickles absent or present. Inflorescence 1–2-flowered, with all flowers bisexual. Flowers 5-merous. Pedicels at anthesis 6–13 mm long, same thickness throughout, 0.5–0.6 mm thick at mid-point, prickles absent. Calyx tube at anthesis 2.5–3 mm long. Calyx lobes at anthesis attenuate, 1.5–2 mm long. Calyx prickles at anthesis absent or present, 0–4 per flower, 1–4 mm long. Calyx stellae very dense, yellow or white or purple, 0.3–0.5 mm across, stalks 0 mm long, lateral rays 7–8. Calyx stellae central ray 0.5–1 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla purple, 7–10 mm long, deeply lobed, inner surface glabrous. Anthers 3.7–4.6 mm long. Ovary glabrous. Functional style 7.5–9 mm long, protruding between anthers or erect near base, then bent, displacing one anther, glabrous. Stigma expanded, obtuse or lobed.

Fruits. Fruiting calyx lobes less than half length of mature fruit or lobes more than half length of mature fruit, prickles absent or present, prickles 2–4 mm long. Mature fruits 1–2 per inflorescence, globular, 11–13 mm diameter, yellowish-green, 2-locular. Mature fruits placenta sessile, semi-circular or sessile, elliptical. Mature fruits interior juicy, succulent, pericarp 0.2–0.5 mm thick. Pedicels at fruiting stage 12–20 mm long, 0.9–1 mm thick at mid-point. Seeds pale yellow, 2.5–2.7 mm long.

Distribution and habitat. Queensland. Qld: Mitchell, Gregory South.

Miscellaneous. Subg. Leptostemonum. Data source: specimens.

Illustrations. • flowers and fruit. • habit. • flower.


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

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