Solanum lucani Mueller (1893: 175)

Bean, A. R., 2012, A taxonomic revision of the Solanum echinatum group (Solanaceae), Phytotaxa 57 (1), pp. 33-50 : 41-43

Solanum lucani Mueller (1893: 175) ( Fig. 6C ).

Type:— AUSTRALIA. Western Australia: Cambridge Gulf , anno 1886, A. Lucanus s.n. (lectotype MEL! [ MEL11346 ] ; isolectotypes K, MEL! ), designated by Symon (1981: 199).

Solanum longissimum Bean (2004: 795) , syn. nov. Type:— AUSTRALIA. Queensland: Pannikan Springs area , 29 km W of Mungana, 26 January 1993, A.R. Bean 5617 & P.I. Forster (holotype BRI!; isotype DNA!).

Illustration: Bean (2004: 797), as S. longissimum

Prostrate shrub 0.1–0.3 m high. Adult branchlets rusty or brown; prickles 3–80 per decimetre, straight, acicular, 1–5 mm long, 6–12 times longer than wide, glabrous; stellate hairs dense, 0.6–1.1 mm in diameter, the stalks 0–0.6 mm long, the central ray 1–1.8 times as long as laterals. Adult leaves simple, the blades ovate or broadly ovate, 3–8 cm long, 1.7–4 cm wide, 1.6–3.0 times longer than broad. Upper surface green or greygreen, prickles absent; stellate hairs moderate density to dense, spaced 0.25–0.5 mm apart, 0.6–0.7 mm across, the stalks 0–0.1 mm long, the central ray 1–1.8 times as long as laterals. Lower surface yellowish, prickles absent; stellate hairs moderate to dense, spaced 0.1–0.3 mm apart, 0.6–0.8 mm diameter, the stalks 0–0.2 mm long, the central ray 0.8–1.5 times as long as laterals; entire, the base cuneate or obtuse, the oblique part 0–5 mm long, obliqueness index 0–12 percent, the apex acute or obtuse; petioles 2.4–5.5 cm long, 55–115 % length of lamina, prickles absent or present. Inflorescence 3–4-flowered, with common peduncle 27–70 mm long, rachis prickles present; pedicels at anthesis 4–12 mm long, prickles present; calyx tube 2.5–3.5 mm long, the lobes deltate, 1–2.5 mm long; calyx prickles absent or present at anthesis, 0–100 per flower, 1–1.5 mm long; calyx stellae very dense, yellow, 0.5–0.9 mm across, the stalks 0–1.5 mm long, central ray 1–1.8 times as long as laterals. Corolla purple, 8–14 mm long, the inner surface glabrous; anthers 3.5–5.5 mm long; free part of the filaments 2.6–3.3 mm long; style 6–10 mm long, strongly bent near base, eccentric, glabrous. Fruiting calyx almost closed at the apex rendering fruit almost invisible; stellate hairs greatly varying in size, some with stalks exceeding 0.8 mm long, proto-prickles often present; prickles>100, 1– 5 mm long, straight, glabrous or with stellae attached near their base; pedicels 15–30 mm long. Mature fruits 1–2 per inflorescence, oblate, 14–19 mm diameter, interior moist but not juicy, the pericarp 1.3–1.7 mm thick; placenta stalked, anvil-shaped. Seeds 2.3–2.8 mm long.

Distribution and habitat: — Solanum lucani occurs throughout tropical Australia from Cape York Peninsula, Queensland to the Kimberley region of Western Australia ( Map 3 ). It occurs in eucalypt forest or woodland, commonly on gravelly rises, laterite or sandy plains, occasionally on sandstone ranges.

Phenology: — Flowers and fruits have been recorded for most months of the year.

Representative specimens examined: — AUSTRALIA. Western Australia: Karunjie Station , February 1959, J.B. Ritson 26 ( CANB). Northern Territory: 94 miles [151 km] E of Daly Waters , 20 March 1972, N. Byrnes 2557 ( CANB, DNA); Banyella, Blue Mud Bay , 2 May 1993, C.R. Dunlop 9441 & G.J. Leach (DNA); ca. 18 miles [29 km] NE of Pine Creek township , 11 March 1965, M. Lazarides & L. Adams 159 ( CANB); Tin Hole Creek, Nicholson River area , 11 June 1974, J.R. Maconochie 2025 ( BRI, CANB, DNA); 12 miles [19 km] S of Adelaide River township , 14 February 1972, J. McKean B343 ( CANB, DNA); Ditchi Outstation, 14.3 km from Port Keats , 2 November 2000, A.A. Mitchell 6418 ( CANB); Arnhem Land , 50 km ENE of Maranboy, 13 June 1972, D.E. Symon 7640 ( CANB, DNA); Pine Creek , 3 April 1980, D.E. Symon 11998 ( CANB); 6 miles [10 km] E of Lost Creek and 4 miles [6 km] W of Victoria River Crossing , 20 April 1980, D.E. Symon 12131 ( CANB). Queensland: Gugu Yalungi main camp ( Laura ), 8 March 1975, B. Hyland 8089 ( BRI); 2.1 km by road from Croydon towards Normanton , 2 February 2007, K.R. McDonald KRM6086 ( BRI); 75.9 km by road W of Georgetown, near Gilbert River , 3 February 2010, K.R. McDonald KRM8700 ( BRI, CANB); 16 km (by road) W of Musselbrook Mining camp on road to Border Waterhole , 175 km N of Camooweal, 25 April 1995, M.B. Thomas MRS179 & R.W. Johnson ( BRI); Gilberton , 10 May 2007, B.S. Wannan 4757 & M. Spry ( BRI).

Notes: — Solanum lucani is closely allied to S. echinatum , but differs by the longer petioles (55–115% of lamina length), the shorter calyx lobes (1–2.5 mm long), the longer filaments (2.6–3.3 mm long) and the fewer prickles on the branchlets (3–80 per decimetre).

The distributions of these species overlap extensively ( Maps 1 and 3 ), and there is evidence of some morphological intergradation between them, as some herbarium specimens are difficult to place.

This species was recently superfluously named S. longissimum by the present author ( Bean 2004). An examination of the type of S. lucani has established that the two names refer to the same taxon.

Figures

MAP 1. Distribution of Solanum echinatum (circles); Solanum wilkinsii (triangles); Solanum medicagineum (stars).

MAP 3. Distribution of Solanum lucani (circles); Solanum rhaphiotes (triangles).

FIGURE 6. Solanum hair types. A. section of fruiting calyx of S. echinatum showing prickles and hairs; B. section of upper leaf surface of S. rhaphiotes; C. a stellate hair from S. lucani; D. section of upper leaf surface of S. lapidosum. A from Harris 432; B from Russell-Smith 556; C from Thompson WES122; D from Fox 431. Scale bar: A = 2 mm, B = 0.3 mm, C = 0.25 mm, D = 0.3 mm.