Solanum species of eastern and northern Australia

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A. R. Bean

Solanum tetrathecum

Habit. Erect, herbaceous resprouter, 0.2–0.5 m high.

Branchlets. Branchlets grey or yellow. Branchlet prickles 1–20 per decimetre, straight, acicular, 3–10 mm long, 7–15 times longer than wide, glabrous. Branchlet hairs stellate. Branchlet stellae very dense, 0.4–0.6 mm diameter, stalks 0–0.1 mm long. Branchlet stellae lateral rays 6–9, porrect. Branchlet stellae central ray absent or present, 0–1 times as long as laterals, not gland-tipped, rigid.

Leaves. Leaves elliptical or ovate, entire. Leaves 3–7 cm long, 1.1–3.2 cm wide, 2.2–3.2 times longer than broad. Leaf apex obtuse, base cuneate or obtuse. Leaf oblique part 0–3 mm long, obliqueness index 0–4 percent. Petioles 0.4–2.2 cm long, 11–30% length of lamina, prickles absent.

Upper leaf surface. Upper leaf surface green. Upper leaf surface prickles absent or present on midvein only, 0–3, straight, acicular, 5–11 mm long. Upper leaf surface stellate hairs confined to midrib or distributed throughout, hair density absent from surface or very sparse or sparse. Upper leaf surface stellae 0.4–1.6 mm apart, 0.25–0.5 mm across, stalks 0 mm long. Upper leaf surface stellae lateral rays 7–8, 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 or present throughout. Upper leaf surface Type 2 hairs 0.1–0.5 mm apart.

Lower leaf surface. Lower leaf surface white, grey or yellowish. Lower leaf surface prickles absent. Lower leaf surface stellate hair density dense or very dense. Lower leaf surface stellae c. 0.1 mm apart, 0.4–0.7 mm diameter, stalks 0–0.1 mm long. Lower leaf surface stellae lateral rays 7–9, porrect. Lower leaf surface stellae central ray 0.7–1.2 times as long as laterals, not gland-tipped. Lower leaf surface simple hairs absent. Lower leaf surface Type 2 hairs absent.

Inflorescence. Inflorescence leaf-opposed or supra-axillary, solitary or cymose (pseudo-racemose). Inflorescence common peduncle 3–11 mm long. Inflorescence rachis prickles absent. Inflorescence 1–3-flowered, with some bisexual and some male flowers. Flowers 5-merous. Pedicels at anthesis 5–12 mm long, same thickness throughout, 0.8–1.3 mm thick at mid-point, prickles absent. Calyx tube at anthesis 3–4.5 mm long. Calyx lobes at anthesis deltate, 1–3.5 mm long. Calyx prickles at anthesis absent. Calyx stellae dense or very dense, yellow, 0.25–0.4 mm across, stalks 0–0.1 mm long, lateral rays 7–10. 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 mauve or purple, 8–15 mm long, deeply lobed, inner surface sparsely stellate-hairy or densely stellate-hairy. Anthers 5–7 mm long. Ovary with Type 2 hairs only. Functional style 8.5–12.5 mm long, protruding between anthers, with stellate and Type 2 hairs. Functional style stellae 0.1–0.2 mm across, lateral rays c. 6, central ray c. 1 times as long as laterals.

Fruits. Fruiting calyx lobes less than half length of mature fruit or lobes more than half length of mature fruit, prickles absent. Mature fruits 1 per inflorescence, globular, 12–17 mm diameter, yellowish-green or green, often streaked, 4-locular. Mature fruits placenta sessile, semi-circular or stalked, anvil-shaped. Mature fruits interior moist but not juicy, pericarp 0.6–1.1 mm thick. Pedicels at fruiting stage 8–14 mm long, 0.8–1.3 mm thick at mid-point. Seeds pale yellow or black, 2.7 mm long.

Distribution and habitat. Queensland. Qld: Moreton, Darling Downs, Burnett. Wet eucalypt forest with rainforest understorey, or rainforest margins, semi-evergreen vine thicket or brigalow/belah, shrubby eucalypt woodland, remote from rainforest.

Miscellaneous. Subg. Leptostemonum. Data source: specimens.

Illustrations. • flower and fruits. • fruit.


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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