Cyanthillium cinereum (L.) H.Rob., Proc. Biol. Soc. Washington 103(1): 252. 1990.

Bunwong, Sukhonthip, Chantaranothai, Pranom & Keeley, Sterling C., 2014, Revisions and key to the Vernonieae (Compositae) of Thailand, PhytoKeys 37, pp. 25-101 : 58-60

Cyanthillium cinereum (L.) H.Rob., Proc. Biol. Soc. Washington 103(1): 252. 1990.

Conyza cinerea L., Sp. Pl.: 862. 1753.

Vernonia cinerea (L.) Less., Linnaea 4: 291. 1829.

Type.

Sri Lanka, Herb. Hermann 3: 16, No. 419 (BM, lectotype designated by Jeffrey 1998: 224). Fig. 7A .

Description.

Annual herbs, 20-100 cm tall. Stems erect, conspicuously ribbed, sericeous. Leaves 3-5 by 2-3 cm, lanceolate or ovate to broadly ovate, margin undulate to serrate, apex acute to acuminate, base attenuate, chartaceous; upper surface sericeous without glands; lower surface sericeous with cylindrical hairs, T-shaped hairs and capitate glands, lateral veins 5-7-paired; petioles up to 2 cm long. Capitulescences terminal or axillary, paniculate. Capitula campanulate, 5-6 mm long, pedunculate. Receptacle flat, 2-2.5 mm in diam., glabrous. Involucres campanulate, in 3-4 series, 4-4.5 mm long, 2.5-3 mm in diam. Phyllaries imbricate, green with purple apex, margin piliferous, outer surface sericeous glandular; the outer and the middle ones lanceolate, apex acute to acuminate; the inner ones lanceolate to oblong, apex acuminate. Florets 25-30; corollas funnelform, purple or white, puberulous glandular; corolla tubes 3-3.5 mm long; corolla lobes ca. 1 mm long. Anthers ca. 0.6 mm long, apical appendage acute, base obtuse. Styles purple, ca. 3 mm long, branches ca. 0.5 mm long.Achenes clavate, 1.5-1.8 mm long, ribs inconspicuous, densely pubescent with twin hairs and capitate glands. Pappus in 2 series of bristles, the inner ones 3-3.5 mm long, persistent.

Distribution.

Thailand: Mae Hong Son, Chiang Mai, Chiang Rai, Phitsanulok, Nakhon Sawan, Phetchabun, Loei, Nong Bua Lum Phu, Udon Thani, Nong Khai, Sakon Nakhon, Nakhon Phanom, Mukdahan, Kalasin, Maha Sarakham, Khon Kaen, Chaiyaphum, Nakhon Ratchama, Ubon Ratchathani, Kanchanaburi, Lop Buri, Saraburi, Nakhon Nayok, Bangkok, Chumphon, Ranong, Phangnga, Phuket. Tropics and subtropics.

Specimens examined.

Thailand, Khon Kaen, Khon Kaen University, 16°28.03'N, 102°49.71'E, S. Bunwong 22 (KKU); Khon Kaen University, 2 Nov 1973, T. Boonkird 66 (BK); Chiang Rai, 20 Jan 1981, Y. Paisooksantivatana 495-81(BK); Chiang Rai, 22 Jan 1981, Y. Paisooksantivatana 521-81(BK); Chiang Rai, 27 Jan 1981, Y. Paisooksantivatana 548-81(BK), Chiang Mai, Doi Pui, 10 Mar 1982, Y. Paisooksantivatana 843-82 (BK); Nan, Muang District, 29 Nov 1986, Y. Paisooksantivatana 1887-86 (BK); Loei, Phu Kra Dung, 12 Jan 1960, L.B. & E.C. Abbe & T. Smitinand 2470 (BKF); Udon Thani, 23 Mar 1988, Parikarn 11 (BK); Nakhon Phanom, 13 May 1932, A.F.G. Kerr 21420 (BK, BM, E); Chaiyaphum, 1 Sep 1988, Parikarn & Prayad 95 (BK); Kanchanaburi, Si Sa Wat, 19 May 1962, Kasem 156 (BK); Saraburi, 23 Dec 1973, J.F. Maxwell 73-789 (AAU, BK); Bangkok, 28 Oct 1992, W. Somprasong 112 (BK); Ranong, 3 Dec 1928, A.F.G. Kerr 16459 (BK, BM, K),

Diagnostic characters.

The species is a widespread weed of disturbed areas throughout the tropics. It is widely known by its former name, Vernonia cinerea . Its leaf shape and capitula size are vary continuously so that plants in dry areas frequently have small capitula and leaves while those in more mesic situations have larger heads and leaves.

Ecology.

Open areas of dipterocarp or dry evergreen forest, alt. 0-250 m; flowering January to December.

Vernacular name.

Mor Noi (หมอน้อย), Kan Toop (ก้านธูป), Tua Haa Din (ถั่วแฮะดิน), Fa Rang Kok (ฝรั่งโคก), Suea Sam Kha (เสือสามขา), Ya Dok Kao (หญ้าดอกขาว), Ya La Ong (หญ้าละออง).

Figures

Figure 7. Morphology of Vernonieae in Thailand 3. A Cyanthillium cinereum B Cyanthillium montanum C Cyanthillium patulum D Decaneuropsis cumingiana E Decaneuropsis eberhardtii F Decaneuropsis garrettiana.