Pluchea Cass.

Shrubs or undershrubs, rardy herbs, often aromatic, glabrous or pubescent, sometimes glandular. Leaves alternate, simple, entire or toothed, sometimes auricled or decurrent on the stem mostly with a prominent midvein, sessile or petiolate. Heads white, yellow or purple, heterogamous, disciform, few or many in terminal, leafless corymbs or subsolitary, small. Involucre ovoid or broadly campanulate; involucral bructs in few unequal series, ovate or obtuse, often with scarious margins. Receptacle flat, naked. Ray florets numerous; corolla often purplish upwards, slender, apically 2-3 -toothed. Disc florets few or many; corolla tubular, campanulate; limb 5-lobed. Achenes cylindrical, prominently 3- 6-ribbed, strigose, often glandular. Pappus of strigose, basally united bristles, in one series.

Tropical and subtropical countries; ca 30 species, 6 in India.

Literature. GILLIS, W.T. (1977). Pluchea revisited. Taxon 26: 587-591. GODFRAY, R.K. (1962). Pluchea setion Stylimnus in North America. J. Elisha Mitch. Sci. Soc. 68: 238-271. pl. 20-23. ROBINSON, J. & J. CUATRECASAS (1973). The generic limits of Pluchea and Tessaria (lnuleae, Asteraceae). Phytologia 27: 277-285.

KEY TO THE SPECIES

1a. Heads subsolitary

1. Pluchea arguta

b. Heads in compound corymbs

2

2a. Leaves 10-20 cm long, linear, margins recurved; annual herbs

4. Pluchea linearifolia

b. Leaves not more than 8 cm long, oblong, obovate or lanceolate, margins not recurved; shrubs or undershrubs

3

3a. Leaves subsessile, gland-dotted; stems nearly glabrous

2. Pluchea indica

b. Leaves sessile, not gland dotted; stems pubescent or hairy

4

4a. Outer involucral bracts oblong, obtuse

3. Pluchea lanceolata

b. Outer involucral bracts ovate, acute

5

5a. Leaves sharply serrate-dentate; achenes glabrous

5. Pluchea tomentosa

b. Leaves entire or obscurely dentate; achenes with few bristles

6. Pluchea wallichiana

List of Lower Taxa