Synonymy

Solanum hamulosum C.T. White, Contr. Arnold Arbor. 4: 95 (1933)

T: Boonjie, Atherton Tableland, Qld, 23 Sept. 1929, S.F. Kajewski 1222; holo: BRI; iso: K.

Description

Scrambling shrub to 4 m, green; leaves pubescent with minute stellate hairs, the hairs sparse on upper surface, dense on lower surface; prickles 2-3 mm long, common on stems and petioles, scattered on juvenile leaves, few or absent on mature leaves; leaves discolorous.

Mature leaves ovate to ovate-elliptic; lamina mostly 10-15 cm long, 6-9 cm wide, entire to shallowly lobed; petiole 2-6 cm long. Juvenile leaves broadly elliptic, the lamina up to 20 cm long, 13 cm wide, lobed; lobe margins shallowly lobed; petiole 6-7 cm long.

Inflorescence to 12-flowered; peduncle 5-10 mm long; rachis up to 10 mm long; pedicels 10-15 mm long, longer in fruit. Calyx 5-6 mm long; lobes broadly lanceolate, 3-5 mm long, sometimes several fused. Corolla stellate, deeply incised, 15-35 mm diam., light purple. Anthers 5-6 mm long.

Berry globular, 15-35 mm diam., ripe colour not known; fruiting pedicel 15-40 mm long. Seeds 1.5-2 mm long, yellow-orange.

Description from Flora of Australia 29: 159 (1982). This circumscription included elements of S. eminens A.R.Bean

Erect, perennial vine, 1.5–7 m high. Juvenile branchlets with 30–40 prickles per dm, 2–3 mm long; leaves (in outline) broadly ovate, shallowly-lobed, with 4–6 pairs of lobes; lamina 18–22 cm long, 9–13 cm wide, with 50–100 prickles on upper surface. Adult branchlets grey to rusty or brown; prickles 50–140 per decimetre, curved, broad-based, 1–3.5 mm long, 1–2.5 times longer than wide; stellae very dense, 0.3–0.4 mm diameter, stalks 0–0.4 mm long; lateral rays 7–10, porrect or ascending; central ray 0.5–1 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent.

Adult leaves ovate, entire; lamina 11–15 cm long, 5–6.5 cm wide, 1.7–2.4 times longer than broad, apex acute or acuminate, base cuneate, obtuse or cordate, oblique part 0–6 mm long, obliqueness index 0–6 percent; petioles 1.9–3.8 cm long, 17–25% length of lamina, prickles present. Upper leaf surface green or grey-green; prickles 0–10, straight, broad-based, 2.5–7 mm long, prickles absent or present on midvein only or present on midvein and lateral veins; stellate hairs distributed throughout; protostellae present; ordinary stellae sparse to dense, 0.2–0.3 mm apart, 0.25–0.4 mm across, sessile; lateral rays 6–8, porrect; central ray 0.7–1.2 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent. Lower leaf surface white or yellowish; prickles 1–6, curved, broadbased, prickles present on midvein only; stellae dense, 0.1–0.15 mm apart, 0.4–0.5 mm diameter, stalks 0–0.1 mm long; lateral rays 8–9, porrect; central ray 0.7–1.5 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent.

Inflorescence supra-axillary, pseudo-racemose, common peduncle 0–5 mm long, rachis prickles absent or present; 5–11-flowered, weakly andromonoecious, flowers 5-merous; pedicels 8–18 mm long at anthesis, markedly thicker distally, 0.5–0.6 mm thick at mid-point, prickles absent. Calyx tube 2–3.5 mm long, lobes deltate, 2–3.5 mm long; prickles absent at anthesis; stellae dense to very dense, white, brown or rusty, 0.25–0.5 mm across, stalks 0–0.2 mm long, lateral rays 7 or 8, central ray 0.7–1.2 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent. Corolla mauve, 9–15 mm long, shallowly or deeply lobed, inner surface sparsely stellate hairy; anthers 4.5–6 mm long; ovary with stellate hairs only; functional style 8–8.5 mm long, erect, with stellate hairs only, stellae 0.3–0.5 mm across, lateral rays 6–8, central ray 0.7–1.2 times as long as laterals.

Fruiting calyx with lobes less than half length of mature fruit, prickles absent. Mature fruits 1 or 2 per inflorescence, globular, 13–15 mm diameter, yellowish-green or green, 2-locular; placenta in cross-section sessile, semi-circular, or stalked, anvil-shaped; mesocarp moist but not juicy; exocarp 0.8–1 mm thick; pedicels 18–25 mm long in fruit, 0.8–1.2 mm thick at midpoint; seeds pale yellow, 2–2.5 mm long.

Description reproduced from Bean (2004) with permission.

Distribution and ecology

Known only from the Atherton Tabeland, Qld, in disturbed rainforest, where it grows on basalt soils between 600-1100 m altitude.

Common name

Dirran Curse. An early local name on the Atherton Tableland for what was considered to be a terrible weed because of its ability to quickly choke timber tracks if left undisturbed.

Relationships

Closest and similar to S. dimorphispinum from which it differs in the characteristics of the stellate hairs (Bean 2004). Hairs in S. hamulosum are stalked, larger (0.3-0.4 mm diameter) and with a central ray whereas those of S. dimorphispinum are sessile, smaller (0.15-0.25 mm diameter) and lacking a central ray. Fruits in S. hamulosum are also smaller (13-15 mm diameter) than those of S. dimorphispinum (30-35 mm diameter).

S. eminens from Bellenden Ker was described by Bean in 2004. Specimens were previously treated as S. hamulosum in the Symon (1981) and Purdie et al. (1982) treatments. The two species differ by

entire (S. hamulosum) vs lobed leaves (S. eminens )
upper leaf surface with 0-10 prickles and moderate to dense indumentum (S. hamulosum), 40-120 prickles and sparse indumentums in S. eminens
green fruits (S. hamulosum), orange fruits (S. eminens)

Symon (1981) considered that S. dimorphispinum C.T. White and S. hamulosum C.T. White were related not to other Australian species but to species of sect. Micrantha from Central and South America; he considered both species were possibly early introductions into Australia.

This hypothesis has been rejected by Bean (2004) because of the closeness of their relationship to other Australian species such as those of the S. macoorai group of subgen. Leptostemonum. Bean defined a new group, the S. hamulosum group, consisting of these two species and a newly described species, S. eminens, from Australia, probably also including some Malesian species from New Guinea and the Philippines.

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Selected specimens

QLD: COOK DISTRICT: Tarzali, the Dirran and Russell River road, Feb 1918, White s.n. (BRI); Millaa Millaa, Sep 1937, Henry s.n. (QRS); R310, Boonjie, Aug 1961, Hyland AFO 2041 (QRS); near Boonjie, May 1967, Symon 4750 (BRI); Davies Creek S.F., Aug 1973, Moriarty 1371 (BRI, CANB); western foothills of Mt Bartle Frere, Aug 1973, Moriarty 1434 (BRI, CANB); S.F.755, T.R.1230, Boonjie L.A., Dec 1974, Irvine 1094 (BRI, QRS); Herberton Range, McKell Road turnoff, Aug 2003, McDonald KRM1165 (BRI). NORTH KENNEDY DISTRICT: Ravenshoe, Sep 1937, Brass & White 132 (BRI); Keogh’s block, ‘Bellview’, Evelyn, Jan 1974, Collins C74-12 (BRI).

Specimens cited by Bean (2004).

Plant status, if any

This species is listed as rare under theQueensland Nature Conservation Act, 1992.

From the web

Further information and links for this species can be found on the Solanaceae Source site.