Spilanthes Jacq.

Herbs, annual, erect or prostrate-decumbent, sometimes rooting at nodes; stems branched, glabrous or pubescent. Leaves simple, opposite, ovate or elliptic, entire or shallowly toothed, glabrous or pubescent with short, simple hairs, generally trinerved. Inflorescence of solitary or few heads arising in the axils or terminal; peduncles slender, elongate. Heads yellow, white or purplish, radiate to discoid, globose to elongate-conical. Involucral bracts 1 - 2 seriate, lanceolate. Oblong to ovate, obtuse or sometimes mucronulate. Ray florets when present few, 1 - 2 seriate, showy; corolla 2 - 3 sinuate-toothed. Style branches slightly exserted. Disc florets many, bisexual; corolla tubular, 5-lobed. Style arms short, truncate. Achenes brown to black, margins ciliate. Pappus of 2 - 3 weak bristles or absent.

Distributed in C. and S. America, Myanmar, Malay peninsula, Indonesia, Philippines, Australia and Africa; ca 75 species, 6 in India.

Literature. KOSTER, J.T. & PHILIPSON, W.R. (1950). Nomenclatural changes in Spilanthes and Blainviilea with remarks and a kew to the specie. of Spilanthes in Malay archipelago. Blumea 6: 349-345. MOORE, A.H. (1907). Revision of the genus. Spilanthes. Proc. Amer. Acad Arts & Sci. 41: 511-569.

KEY TO THE SPECIES

1a. Achenes eciliate; pappus absent

1. Spilanthes calva

b. Achenes ciliate; pappus present (sometimes absent in S. oleracea)

2

2a. Heads rayed

3

b. Heads discoid

4

3a. Heads 1 cm across; ray florets 8-12

2. Spilanthes ciliata

b. Heads 4-5 mm across ray florets 5-6

6. Spilanthes uliginosa

4a. Heads white

5. Spilanthes radicans

b. Heads yellow or reddish-brown

5

5a. Heads large, 1-2 cm across; achenes monomorphic

3. Spilanthes oleracea

b. Heads small, 4-5 mm across; achenes dimorphic

4. Spilanthes paniculata

List of Lower Taxa