Crotalaria juncea Linnaeus (1753: 714)

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

18. Crotalaria juncea Linnaeus (1753: 714) . Type (lectotype designated by Polhill 1971):— INDIA. Clifford s.n.

(lectotype BM000646565). ( Figures 30J & 30K ).

= Crotalaria tenuifolia Roxburgh (1814: 54) . Type (lectotype designated here):— INDIA. 1813, Wallich 5368 (lectotype K-W K001120703 , isolectotypes K-W K001120704 , K-W K001120705 ).

Herb, erect, 0.8–2 m high; young branches terete, brown pubescent. Leaves simple. Stipules narrowly linear, 1–2 mm long, caducous. Petioles 1–2.5 mm long, brown pubescent. Lamina oblong, 2–9.5 × 0.5–1.8 cm, base obtuse, apex acute or obtuse, margin entire, both surfaces pilose; lateral veins 8–13 pairs. Inflorescences terminal or axillary, open racemes, 12–23 cm long; peduncle 2.8–3 cm long, brown pubescent. Bracts triangular, 2–4 mm long, persistent. Pedicels 5–7 mm long, brown pubescent. Bracteoles inserted distally on the pedicel, narrowly linear, 2–3 mm long, caducous. Calyx 1.5–2 cm long, campanulate, bilabiate; tube 2–3 mm long; lobes triangular, 1.3–1.8 cm long, glabrous inside, brown pubescent outside. Corolla yellow. Standard: claw 1–1.2 mm long, glabrous, margin white tomentose; blade elliptic, 14–15 × 7–8 mm, base rounded, apex obtuse, margin glabrous. Wings: claw 1.8–2 mm long, glabrous; blade oblong, 10–12 × 3–4 mm, base oblique white puberulous, apex acute, margin glabrous. Keel: claw 1–1.2 mm long, glabrous, margin white tomentose; blade lanceolate, 17–18 × 6–8 mm, beak spirally twisted, base obtuse with white tomentum, apex attenuate, margin brown pubescent. Stamens: filaments fused for proximal 2–4 mm, free for distal 11–13 mm; anthers either narrowly linear, 4–4.3 mm long or oblong, 0.8–1 mm long. Ovary sessile, elliptic, 6–7 mm long, brown pubescent; style 1.7–1.9 cm long, adaxially white pubescent in a single line along the distal edge, abaxially glabrous. Pods sessile, oblong, 2.3–3 × 0.8–1 cm, brown with brown pubescence. Seeds reniform, 4.5–5 × 4–4.5 mm, brown-green.

Representative specimens:— CAMBODIA. Mondulkiri: 28 October 2006, Cheng & Leti CL 328 ( P) . LAOS. Savannakhet: 30 December 1924, Poilane 11402 ( AAU, L, P) . Sayaboury : January 1953, Vidal 2133 ( P) . MALAYSIA. Johor: Layang-Layang , 26 August 1936, Roger & Schofield 31185 ( SING) . MYANMAR. Taong Dong : 1826, Wallich 5363 ( K) . No locality, October 1888, Khan 240 ( P) . THAILAND. Chanthaburi: Pong Nam Ron, Pailin , 28August 1978, Larsen et al. 32196 ( AAU) . Chiang Mai: Doi Suthep , 30 October 1994, Nanakorn et al. 2592 ( QBG) . Kanchanaburi: Mueang , 15 November 1967, Chermsirivathana 802 ( BK) . Khon Kaen: Phu Pha Man National Park , 23 August 2015, Ninkaew 393 ( KKU) . Loei: Na Haeo , 27 April 1995, Nanakorn et al. 3263 ( QBG) . Mae Hong Son: Phang Ma Pha , 9 August 2010, Watthana 3498 ( QBG) . Nakhon Phanom: 7 February 1924, Kerr 8434 ( BK) . Nakhon Ratchasima: Mueang , 9 August 2014, Ninkaew 280 ( KKU) . Nan: Tha Wang Pha , 2 March 2002, Srisanga et al. 2499 ( QBG) . Phayao: Mueang district, 4 km N of Phayao University , 19 February 2016, Balslev & Bunma 8695 ( AAU, BKF, QBG,) . Sakon Nakhon: Phu Phan Ratchaniwet , 10 December 1980, Umpai 620 ( BK) . Saraburi: Ban Nong Bua , 4 October 1927, Put 1144 ( ABD, BK) . Surat Thani: Khanom, Khuan Thong Village , 13 August 2013, Insorn 2 ( PSU) . Tak: Mueang , 17 December 1999, Sasirat 194 ( QBG) . VIETNAM. Ninh Binh: October 1922, Petelot 1105 ( HNU) .

Distribution: —North America, Africa, Asia ( India, Myanmar, China, Thailand, Laos, Cambodia, Vietnam, Malaysia), Australia. ( Figure 11 ).

Ecology: —Roadsides and open places in paddies, elevation 15–750 m.

Notes: — Crotalaria juncea is cultivated for its fibre and it is used as green manure and as an ornamental plant. This species is recognized by its distinctive brown pubescent and oblong pods, with densely silvery pubescent hairs and calyx. The standard is perpendicular to the keel. There are three duplicates of the original material of C. tenuifolia without indication of lectotype; therefore lectotypification is designated here.

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.