Synonymy
Solanum defensum F.Muell., Fragm. 5: 193 (1866).
T:
S. discolor auct. non R.Br.: Symon, J. Adelaide Bot.Gard. 4: 141(1981), p.p.
Description
Erect, rhizomatous perennial shrub, 1-2.5 m high. Juvenile branchlets with 25-30 prickles per dm, 6-9 mm long; leaves (in outline) elliptical, shallowly-lobed, with 4-6 pairs of lobes; lamina 8-13 cm long, 2.5-4 cm wide, with 10-20 prickles on upper surface. Adult branchlets brown; prickles 1-10 per decimetre, straight, acicular, 4-9 mm long, 13-18 times longer than wide; stellae sparse to dense, 0.25-0.5 mm diameter, sessile; lateral rays 7 or 8, porrect; central ray absent or present, 0-0.4 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent.
Adult leaves ovate, entire or shallowly lobed throughout; lobes 3-6 on each side, obtuse, lobing index 1-1.4; lamina 7-14.5 cm long, 2.3-5 cm wide, 2.1-3.2 times longer than broad, apex acute or acuminate, base cuneate or obtuse, oblique part 0-2.5 mm long, obliqueness index 0-2 percent; petioles 0.6-1 cm long, 6-10% length of lamina, prickles absent or present. Upper leaf surface green; prickles 0-10, straight, acicular, 5-8 mm long, prickles absent or present on midvein only or present on midvein and lateral veins; stellate hairs absent, or confined to midrib; ordinary stellae absent from surface; finger hairs absent; Type 2 hairs absent. Lower leaf surface green; prickles 0-4, straight, acicular, absent or present on midvein only or present on midvein and lateral veins; stellae very sparse to moderate, 0.5-1.7 mm apart, 0.4-0.6 mm diameter, sessile; lateral rays 7 or 8, porrect; central ray 0.2-0.6 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent.
Inflorescence supra-axillary, pseudo-racemose, common peduncle 0-4 mm long, rachis prickles absent; 5-13-flowered, weakly andromonoecious, flowers 5-merous; pedicels 4-8 mm long at anthesis, markedly thicker distally, 0.15-0.25 mm thick at midpoint, prickles absent. Calyx tube 1.5-3 mm long, lobes rostrate, 0.2-1 mm long; prickles absent at anthesis; stellae moderate to dense, transparent, 0.25-0.3 mm across, sessile, lateral rays 7 or 8, central ray 0-0.5 times as long as laterals, not gland-tipped; finger hairs absent; Type 2 hairs absent. Corolla white, mauve or purple, 5-8 mm long, deeply lobed, inner surface sparsely to densely stellate-hairy; anthers 3-4.5 mm long; ovary with stellate hairs only; functional style 3.5-4.5 mm long, erect, with stellate hairs only, stellae c. 0.25 mm across, lateral rays 7-10, central ray 0-1 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, 13-17 mm diameter, red, 1-locular (septum absent or incomplete); placenta in cross-section sessile, elliptical; mesocarp juicy, succulent; exocarp 1.2-1.7 mm thick; pedicels 17-28 mm long in fruit, 0.6-0.8 mm thick at mid-point; seeds pale yellow, 3.8-4.3 mm long.
A.R.Bean's description of this species reproduced, with permission, from Austrobaileya 6: 689 (2004).
Another detailed description of S. defensum can be seen at Bean's interactive key site at http://delta-intkey.com/solanum/www/defensum.htm
Distribution and ecology
Confined to Cape York Peninsula, occurring from the tip to the McIlwraith Range.
It is found in rainforest in hilly areas on soils formed from granitic or metamorphic rocks.
Relationships
This species was treated as a part of S. discolor by Symon (1981). Bean (2004) notes that it is close to S. discolor , S. yirrkalense and S. fervens, all of which occur on Cape York Peninsula, but differs from them by its lower leaf surface being green and either lacking stellate hairs completely or with only a very sparse covering of them.
Bean also notes that specimens lacking flowers or fruits are easily confused with S. macoorai, but this has a more southerly distribution.
S. defensum is placed in the S. ferocissimum group of subgen. Leptostemonum together with S. chenopodinum, S. corifolium, S. discolor, S. dissectum, S. dryanderense, S. dysprosium, S. ferocissimum, S. fervens, S. inaequilaterum, S. latens, S. lythrocarpum, S. mentiens, S. parvifolium, S. shirleyanum, S. stelligerum and S. yirrkalense (Bean 2004).
Selected specimens
QLD: COOK DISTRICT: Leo Creek, Upper Nesbit River, Aug 1948, L.J.Brass 19947 (BRI); Table Range, Dead Horse Creek, Oct 1973, A.Dockrill 760 (QRS); McIlwraith Range, Sep 1974, B.Hyland 7643, 7658 (BRI, QRS); Lockerbie Scrub, Bamaga, Sep 1974, L.Webb & Tracey 13481 (CANB, QRS); ‘Temple Bay’ yards, Sep 1976, B.Hyland 8964 (QRS); northern slopes Mt Tozer, Nov 1977, L.Webb & Tracey 13479 (BRI); near Ginger Mick’s Mine, 2 km S of Punsand Bay, Feb 1990, P.Forster PIF6403 (BRI); 2.2 km from Captain Billy Landing hut, on the Heathlands road, Mar 1992, R.Johnson 5023 (BRI); Claudie Falls, 2.5 km NE of Mt Tozer, Iron Range N.P., May 1992, Fell DF2614 & Jensen (BRI, QRS); Turrel Hill, 10 km WNW of Nesbit River mouth, 51.6 km N of ‘Silver Plains’ HS., Aug 1993, Fell DGF3398 et al. (BRI, CANB); 1.5 km ENE of Lamond Hill, 8.5 km NNW of Lockhart River community, Mar 1994, Fell DGF4139 & Stanton (BRI); Round Mountain, Embley Range, ‘Silver Plains’, Jul 1997, P.Forster PIF21350 et al. (AD, BRI, QRS).
Specimens cited by Bean (2004).
Plant status, if any
Not considered to be at risk (Bean 2004).
From the web
Further information and links for this species can be found on the Solanaceae Source site.