Crotalaria incana Linnaeus (1753: 716)

Ninkaew, Sakuntala, Balslev, Henrik, Pornpongrungrueng, Pimwadee & Chantaranothai, Pranom, 2017, Crotalaria L. (Fabaceae: Faboideae) in continental Southeast Asia, Phytotaxa 320 (1), pp. 448-450 : 448-450

17. Crotalaria incana Linnaeus (1753: 716) . Type (lectotype designated by Polhill 1997):— JAMAICA. Sloane 6 (lectotype searched for, but not located at BM). ( Figures 30H & 30I ).

= Crotalaria incana f. glabrescens Wilczek (1953: 147) . Type:— ZAIRE, Kivu, Kabare, 1914, Bequaert 5355 (holotype BR n.v.).

Herb or shrublet, erect, 0.5–2 m high; young branches angular, silvery pubescent. Leaves digitately 3-foliolate. Stipules narrowly linear, 2–3 mm long, caducous. Petioles 0.5–6 cm long, silvery pubescent. Petiolules 1–3 mm long. Leaflets obovate or elliptic, 0.5–7 × 0.3–3.8 cm, base obtuse or cuneate, apex acute or acuminate, margin entire, glabrous, rarely puberulous upper, silvery pubescent lower; lateral veins 5–7 pairs. Inflorescences terminal, open racemes, 7–13 cm long; peduncle 1–5.3 cm long, silvery pubescent. Bracts narrowly linear, 5–7 mm long, caducous. Pedicels 2–3 mm long, brown pubescent. Bracteoles inserted distally on the pedicel, narrowly linear, 2.5–4 mm long, persistent. Calyx 0.8–1.1 cm long, campanulate, bilabiate; tube 1.8–2 mm long; lobes triangular, 6–9 mm long, glabrous inside, silvery pubescent outside. Corolla yellow. Standard: claw 0.5–0.8 mm long, glabrous, apex with appendages; blade obovate, 11–13 × 7–8 mm, base cuneate or obtuse, apex rounded, margin glabrous. Wings: claw 1.5–2 mm long, glabrous; blade oblong, 8–10 × 2–2.5 mm, base oblique, apex acute, margin glabrous. Keel: claw 1–1.5 mm long, glabrous; blade lanceolate, 9–10 × 3.5–4 mm, beak not twisted, base oblique, apex acute, margin white pubescent. Stamens: filaments fused for proximal 2.8–3.5 mm, free for distal 3–6 mm; anthers either narrowly linear, 1.8–2 mm long or oblong, 0.5–0.6 mm long. Ovary sessile, oblong or obovate, 0.9–1 mm long, brown pubescent; style 7–8 mm long, adaxially white pubescent in a single line along the distal edge, abaxially glabrous. Pods sessile, oblong or obovate, 2.7–3.4 × 0.7–0.8 cm, brown with white pubescence. Seeds reniform, 2.5–3 × 2–2.5 mm, brown-green.

Representative specimens: — SINGAPORE. Siglap : 18 February 1950, Sinclair 38874 ( SING) . Telok Kurau : 1899, Ridley 10633 ( SING) . THAILAND. Chumphon: Lang Suan , 1 July 2015, Ninkaew 390 ( KKU) . Krabi: Ao Nang, 12 July 1992, Larsen et al. 43326 ( AAU, BKF, PSU) . Lopburi: Chai Badan , 6 August 1945, Buntuengsuk 13 ( BKF) . Mae Hong Son: Ban Mae Lai , 13 July 2013, Pongamornkul 3700 ( QBG) . Nakhon Ratchasima: Sakaerat Environmental Research Station , 17 June 1989, Niyomdham et al. 2008 ( BKF) . Nakhon Sawan: 20 km south of Nakhon Sawan, 20 July 1973, Murata et al. T-16565 ( AAU, BKF) . Prachinburi: Khao Yai National Park , 7 July 1966, Larsen et al. 66 ( AAU, BKF) . Ranong: 24 August 1977, Phengklai et al. 3830 ( BKF, PSU) . Sa Kaeo: Pang Sida National Park , 4 August 2001, Jaikrasane 99 ( BCU) .

Distribution: —North America, Africa, Asia ( Yemen, Pakistan, India, China, Thailand, Singapore), Australia, Hawaii. ( Figure 11 ).

Ecology: —Roadsides, elevation 8–260 m.

Notes: — Crotalaria incana is distinguished by its digitately 3-foliolate leaves, hairy pods and short (7–13 cm long) terminal inflorescences.

Figures

FIGURE 11. Distribution map of Crotalaria incana and C. juncea in continental Southeast Asia.

FIGURE 30. Crotalaria in continental Southeast Asia: A & B) C. alata; C) C. albida; D) C. assamica; E) C. bracteata; F) C. chinensis; G) C. goreensis; H & I) C. incana; J & K) C. juncea; L) C. medicaginea; M) C. pallida N) C. sessiliflora and O) C. verrucosa.