Solanum species of eastern and northern Australia

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A. R. Bean

Solanum rixosum

Habit. Erect, rhizomatous perennial shrub, 1–2 m high.

Branchlets. Branchlets yellow or rusty. Branchlet prickles absent or present, 0–15 per decimetre, straight, acicular, 3–10 mm long, 10–14 times longer than wide, with scattered Type 2 hairs on lower half. Branchlet hairs stellate. Branchlet stellae very dense, 0.3–0.4 mm diameter, stalks 0–0.2 mm long. Branchlet stellae lateral rays 4–8, porrect. Branchlet stellae central ray 1–2 times as long as laterals, not gland-tipped, thready. Branchlet Type 2 hairs absent.

Leaves. Leaves elliptical or ovate, entire or shallowly lobed throughout. Leaf lobes 0 on each side or 2–3 on each side, obtuse, lobing index 1–1.3. Leaves 6–12 cm long, 2.9–4.8 cm wide, 1.8–2.6 times longer than broad. Leaf apex acute, base cuneate or obtuse. Leaf oblique part 0–4 mm long, obliqueness index 0–4 percent. Petioles 0.7–1.4 cm long, 8–14% 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, 0–10, straight, acicular, 4–10 mm long. Upper leaf surface stellate hairs distributed throughout, hair density very sparse to sparse. Upper leaf surface stellae 0.7–1.6 mm apart, 0.4–0.8 mm across, stalks 0–0.2 mm long. Upper leaf surface stellae lateral rays 6–9, porrect or ascending. Upper leaf surface stellae central ray 1–1.5 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 yellowish. Lower leaf surface prickles absent. Lower leaf surface stellate hair density dense. Lower leaf surface stellae 0.1–0.4 mm apart, 0.5–0.8 mm diameter, stalks 0.2–0.6 mm long. Lower leaf surface stellae lateral rays 7–9, porrect. Lower leaf surface stellae central ray 0.5–1.5 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 1–6 mm long. Inflorescence rachis prickles absent. Inflorescence 2–15-flowered, with some bisexual and some male flowers. Flowers 5-merous. Pedicels at anthesis 6–11 mm long, same thickness throughout, 0.5–0.8 mm thick at mid-point, prickles absent. Calyx tube at anthesis 1.5–3 mm long. Calyx lobes at anthesis attenuate, 7–9 mm long. Calyx prickles at anthesis absent. Calyx stellae dense or very dense, yellow or brown or rusty, 0.5–0.6 mm across, stalks 0–0.2 mm long, lateral rays 8–9. Calyx stellae central ray 1–1.5 times as long as laterals, not gland-tipped. Calyx simple hairs absent, Type 2 hairs absent. Corolla purple, 9–14 mm long, shallowly lobed, inner surface sparsely stellate-hairy. Anthers 5–6 mm long. Ovary with stellate and Type 2 hairs. Functional style 7.5–10 mm long, protruding between anthers, glabrous or with Type 2 hairs only or with stellate and Type 2 hairs. Functional style stellae 0.4–0.5 mm across, lateral rays 6–9, central ray 1–1.5 times as long as laterals.

Fruits. Fruiting calyx lobes less than half length of mature fruit, prickles absent. Mature fruits 1–3 per inflorescence, globular, 19–24 mm diameter, yellowish-green or green, often streaked, 2-locular or 3-locular. Mature fruits placenta stalked, anvil-shaped. Mature fruits interior moist but not juicy, pericarp 0.9–1.2 mm thick. Pedicels at fruiting stage 17–26 mm long, 1–1.4 mm thick at mid-point. Seeds pale yellow, 2.2–2.7 mm long.

Distribution and habitat. Queensland, New South Wales. Qld: Moreton, Darling Downs, Wide Bay, Burnett. NSW: North Coast. Evergreen notophyll rainforest (no eucalypts), wet eucalypt forest with rainforest understorey, or rainforest margins.

Miscellaneous. Subg. Leptostemonum. Data source: specimens.

Illustrations. • plant. • flower. • fruits. • type specimen.


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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