Crotalaria assamica Bentham (1843: 481)

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

5. Crotalaria assamica Bentham (1843: 481) . Type (lectotype designated by Ansari 2008):— INDIA. Assam, Hooker & Thomson s.n. (lectotype CAL n.v.; isolectotype K000591056!). ( Figure 30D ).

Shrublet, 1–3 m high; young branches angular, brown pubescent. Leaves simple. Stipules narrowly linear, 1–4 mm long, brown pubescent, persistent. Petioles 3–5.5 mm long, brown pubescent. Lamina obovate or lanceolate, 3.2–12.5 × 0.7–5 cm, base cuneate, apex acute or obtuse, margin entire, glabrous upper, brown pubescent lower; lateral veins 9–15 pairs. Inflorescences terminal, open racemes, 13–40 cm long; peduncle 8–12 cm long, silvery pubescent. Bracts lanceolate, 5–6 × 0.7–1 mm, persistent. Pedicels 6–10 mm long, brown pubescent. Bracteoles inserted on the pedicel, narrowly linear, 3–5 mm long, caducous. Calyx 10–15 mm long, campanulate, bilabiate; tube 3–5 mm long; lobes triangular, 7–10 mm long, glabrous inside, silvery puberulous outside. Corolla yellow. Standard: claw 2.8–3 mm long, white tomentose above and along the margin, glabrous below; blade orbicular or broadly elliptic, 1.5–1.7 × 1.8–2.3 cm, base cordate, apex rounded, margin glabrous. Wings: claw 3–4 mm long, glabrous; blade elliptic, 16–17 × 8–10 mm, base oblique, apex rounded, margin glabrous. Keel: claw 4–6 mm long, white tomentose above and along the margin, glabrous below; blade ovate, 17–18 × 10–11 mm, beak spirally twisted, base obtuse, apex attenuate, margin white tomentose. Stamens: filaments fused for proximal 1–1.2 cm, free for distal 0.6–1.2 cm; anthers either narrowly linear, 4.5–5 mm long or oblong, 1.2–1.5 mm long. Ovary with 0.5–1 mm long stipe, obovate, 1–1.3 cm long, glabrous; style 1.7–2 cm long, adaxially white pubescent in a single line along the distal edge, abaxially glabrous. Pods with 5–8 mm long stipe, obovate, 5–7.5 × 1.5–2 cm, brown, glabrous. Seeds reniform, 3–5 × 4–5 mm, brown-black.

Representative specimens: — CAMBODIA. Mondulkiri, 29 October 2006, Cheng & Leti CL 359 ( P) . LAOS. Khammouan: Nya Lak , 25 October 2005, Newman et al. LAO535 ( BKF, FOF, L, P) . Luang Prabang: 6 March 1932, Poilane 20352 ( K, L, P) . Savannakhet: Muang Phin , 17 September 1920, Poilane 1901 ( L, P) . Xieng Khouang: April 1952, Vidal 1692 ( P) . MYANMAR: Magway: 8 February 2011, Man 87051 ( QBG) . THAILAND. Chiang Mai: Doi Chiang Dao Wildlife Sanctuary , 15 January 2013, Ninkaew 272 ( KKU) . Chiang Rai: 24 January 1970, Sutheesorn 1410 ( BK) . Nan: Nanthaburi National Park , 19 February 2014, Ninkaew 312 ( KKU) . Rayong: Koh Samet , February 1987, Niyomdham et al. 1312 ( AAU, BKF) . VIETNAM. Cao Bang: Bao Lac , 30 October 1966, Khoi 5339 ( HN) . Lao Cai: Muong Hum , 9 January 1931, Poilane 18843 ( HN, K, L, P) . Nghe An: Vinh, Pu Mat National Park , 26 August 1998, Anon . CH 77 ( HNU) .

Distribution: —Asia ( India, Myanmar, China, Thailand, Laos, Cambodia, Vietnam). ( Figure 4 ).

Ecology: —Open areas in deciduous dipterocarp and evergreen forests, elevation 170–1300 m.

Notes: — Crotalaria assamica is recognized by its lanceolate bracts, caducous bracteoles, terminal inflorescences, hairy pedicel and calyx and stipitate pods.

Figures

FIGURE 4. Distribution map of Crotalaria annamensis and C. assamica 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.