Solanum species of eastern and northern Australia

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A. R. Bean

Solanum medicagineum

Habit. Prostrate, rhizomatous perennial shrub, 0.1–0.3 m high.

Branchlets. Branchlets grey or mauve to purple or brown. Branchlet prickles 25–120 per decimetre, straight, acicular, 1–6 mm long, 7–11 times longer than wide, with dense stellate hairs on lower part. Branchlet hairs stellate. Branchlet stellae very dense, 0.4–0.5 mm diameter, stalks 0–0.4 mm long. Branchlet stellae lateral rays 7–8, porrect. Branchlet stellae central ray 0.8–1.2 times as long as laterals, not gland-tipped. Branchlet Type 2 hairs absent.

Leaves. Leaves broadly ovate, entire. Leaves 2.1–3.8 cm long, 1.3–2.2 cm wide, 1.5–1.8 times longer than broad. Leaf apex acute, base cuneate or obtuse or cordate. Leaf oblique part 0–3.5 mm long, obliqueness index 0–10 percent. Petioles 0.9–2.2 cm long, 32–63% length of lamina, prickles absent or present.

Upper leaf surface. Upper leaf surface grey-green or grey. Upper leaf surface prickles absent. Upper leaf surface stellate hairs distributed throughout, hair density dense to very dense. Upper leaf surface stellae 0.05–0.1 mm apart, 0.3–0.5 mm across, stalks 0–0.25 mm long. Upper leaf surface stellae lateral rays 7–8, porrect. Upper leaf surface stellae central ray 0.8–1.2 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 white, grey. Lower leaf surface prickles absent. Lower leaf surface stellate hair density very dense. Lower leaf surface stellae 0.05 mm apart, 0.4–0.6 mm diameter, stalks 0–0.3 mm long. Lower leaf surface stellae lateral rays 7–8, porrect. Lower leaf surface stellae central ray 0.8–1.3 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 3–9 mm long. Inflorescence rachis prickles present. Inflorescence 1–2(–3)-flowered, with all flowers bisexual. Flowers 5-merous. Pedicels at anthesis 4–8 mm long, prickles present. Calyx tube at anthesis 2.5–3 mm long. Calyx lobes at anthesis deltate or attenuate, 1 mm long. Calyx prickles at anthesis present, 20 per flower, 0.5–1 mm long. Calyx stellae very dense, yellow or white, 0.25–0.35 mm across, stalks 0–0.1 mm long, lateral rays 7–8. Calyx stellae central ray 0.8–1.2 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla purple, 7–9 mm long, rotate or shallowly lobed, inner surface glabrous. Anthers 2.7–3.1 mm long. Filaments 0.6–0.8 mm long. Functional style protruding between anthers, glabrous.

Fruits. Fruiting calyx hypanthium accrescent, enclosing most or all of mature fruit, prickles 2–6 mm long. Mature fruits 1 per inflorescence, oblate, 13–15 mm diameter, green, often streaked, 4-locular. Pedicels at fruiting stage 8–14 mm long, 0.6 mm thick at mid-point. Seeds brown, 1.8–2 mm long.

Distribution and habitat. Northern Territory.

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’.

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