Ethulia conyzoides L., Sp. Pl.: 1171. 1763.

Bunwong, Sukhonthip, Chantaranothai, Pranom & Keeley, Sterling C., 2014, Revisions and key to the Vernonieae (Compositae) of Thailand, PhytoKeys 37, pp. 25-101 : 71

Ethulia conyzoides L., Sp. Pl.: 1171. 1763.

Type.

Egypt, P. Forsskal 1387 (holotype: K!).

Description.

Annual herbs, 50-150 cm tall. Stems erect, conspicuously ribbed, puberulous. Leaves alternate, 5-8 by 1-2 cm, elliptic or lanceolate, margin serrate, apex acuminate or acute, base attenuate, chartaceous; both surfaces ferrugineous with unicellular hairs and capitate glands, shortly petiolate. Capitulescences terminal and axillary, corymbose. Capitula hemispherical, 3-4 mm long. Receptacle ca. 1.5 mm in diam., glabrous. Involucres semispherical, in 3-4 series, 1.5-2 mm long, 1-2 mm in diam. Phyllaries imbricate, green with purple apex, margin piliferous, outer surface puberulous, glands capitate; the outer and the middle ones ovate to lanceolate, apex acute; the inner ones lanceolate to oblong, apex acute. Florets 20-30; corollas funnelform, purple, glandular; corolla tubes 0.5-1 mm long; corolla lobes ca. 1 mm long. Anthers 1.5-2 mm long, apical appendage acute, base obtuse. Styles purple, inner surface covered with stigmatic papillae, sweeping hairs. Achenes turbinate, 1.5-2 mm long, glandular, 6-ribbed. Pappus absent.

Distribution.

Thailand: Chiang Rai, Chiang Mai, Nakhon Phanom. Tropics.

Specimens examined.

Thailand: Chiang Rai, Mae Kok riverbank, Lamnam Kok national park, 19°57.49'N, 99°41.14'E, 14 Jun 1925, H.B.G. Garrett 227 (BKF, BM, K); Nakhon Phanom, 10 May 1932, A.F.G. Kerr 21396 (BK, BM, K); Nakhon Phanom, 9 May 1932, A.F.G. Kerr 21809 (K).

Diagnostic characters.

Ethulia conizoides is distinguished by achenes having 4-6 ribs, pappus and carpopodium are absent.

Ecology.

Open area along river bank in evergreen forest, alt. 200-400 m; flowering May to September.

Vernacular name.

Ya Hua Mud (หญ้าหัวหมุด).