Struchium sparganophorum (L.) Kuntze, Revis. Gen. Pl. 1: 366. 1891.

Bunwong, Sukhonthip, Chantaranothai, Pranom & Keeley, Sterling C., 2014, Revisions and key to the Vernonieae (Compositae) of Thailand, PhytoKeys 37, pp. 25-101 : 91-92

Struchium sparganophorum (L.) Kuntze, Revis. Gen. Pl. 1: 366. 1891.

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

Sparganophoros vaillantii Crantz, Inst. Rei. Herb. 1: 261. 1766.

Ethulia struchium Sw., Prodr. 111. 1788.

Type.

Jamaica (not seen). Figs 10G-H .

Description.

Annual, 20-50 cm tall. Stems erect, inconspicuously ribbed, puberulous. Leaves 4-12 by 2-15 cm, elliptic, pubescent, margin serrate, apex acute, base attenuate, chartaceous; both surfaces puberulous with cylindrical hairs and capitate glands; lateral veins 7-11-paired; petioles up to 12 mm long. Capitulescences axillary, solitary or clustered. Capitula hemispherical, sessile, 4-6 mm in diam. Receptacle convex, 2-2.5 mm in diam., glabrous. Involucres 3-4 series, 3-4 mm long, imbricate, hemispherical. Phyllaries light green, margin piliferous, outer surface puberulous without glands; the outer ovate to lanceolate, apex acute to acuminate; the inner ones obovate-lanceolate, apex acuminate. Florets 50-70; corollas funnelform, white, glandular; corolla tubes 1-1.5 mm long; corolla lobes 3-4, 0.5-1 mm long. Anthers ca. 1 mm long, apical appendage acute, base acute. Styles purple, ca. 2 mm long, branches 1-1.5 mm long, inner surface covered with stigmatic papillae. Achenes turbinate, 3-4-angular, 1-1.5 mm long, 3-5-ribbed, glandular. Pappus of 3-4 parts, coroniform, ca. 1 mm long, whitish.

Distribution.

Thailand: Lamphun, Nakhon Phanom, Kanchanaburi, Bangkok, Ranong, Phangnga, Krabi, Trang, Songkhla, Yala. Tropics.

Specimens examined.

Thailand, Phang Nga, Muang district, 8°26.55'N, 98°31.16'E, 1 Aug 2002, S. Bunwong 28 (KKU); Lamphun, Muang District, 20 Dec 1994, P. Palee 265 (BKF, CMU, L); Bangkok, Klong San, 20 Feb 1971, J.F. Maxwell 71-107 (AAU, BK, L); Lad Yao, 27 Sep 1984, Y. Paisooksantivatana 1433-84 (BK); Ranong, Kra Buri, 10 Apr 1967, C. Chermsirivathana 1266 (BK, L); Kra Buri, S. Sutheesorn 2275 (BK); Ka Pur, 7 Dec 1979, T. Shimizu, H. Toyokuni, H. Koyama, T. Yahama & C. Niyomdham 26302 (AAU, BKF, L); Trang, Khao Chong, 13 Aug 1975, J.F. Maxwell 75-824 (AAU, BK, L); Songkhla, Rattaphume, 3 Aug 1986, J.F. Maxwell 86-636 (AUU, BKF, L); Rattaphume, J.F. Maxwell 86-911 (BKF, L).

Diagnostic characters.

Distinct characters of Struchium sparganophorum are the sessile capitula in axillary head, achenes with coroniform pappus, and florets with 3-4 corolla lobes.

Ecology.

Open sandy grassland or secondary evergreen forest, alt. 50-400 m; flowering August to April.

Vernacular name.

Muk Din (มุกดิน).

Figures

Figure 10. Morphology of Vernonieae in Thailand 6. A Okia birmanica B Okia pseudobirmanica C Pulicarioidea annamica D-E Strobocalyx arborea F Strobocalyx solanifolia G-H Struchium sparganophorum I Tarlmounia elliptica.