Flora of the Malayan Peninsula. 45 
retrorsely barbellate arms. — Distrib. About 120 species, chiefly 
American. 
Bidens pilosa, Linn. Sp. PI. 832. An erect, very variable, glabrous 
pubescent or pilose herb, 6 to 24 in. high ; stems when dry 4-angled. 
Leaves 3-fid to 3-partite, or 2-3-pinnatifid, their segments broadly or 
narrowly ovate to lanceolate, serrate. Heads -3 to -4 in. across, on long 
stout petioles of varying length, terminal or axillary. Bay-flowers 
when present white or yellow, often absent. Involucral bracts shorter 
than the flowers, broadly oblong, with scarious margins. Cypselas 
black, compressed, long, narrow, slender, ribbed; pappus of 3 or 4 
bristles shorter than the cypselas, pale brown. 
Var. 1 pilosa proper, Hook. fil. PI. Br. Ind. III. 309 ; leaves 3-fid 
or 3-sect, their segments broadly or narrowly ovate or lanceolate, 
serrate. B. pilosa, Linn. ; DC. Prod. V. 597 ; Clarke Comp. Ind. 140 ; 
Prain Bengal Plants, 616. B. leucantha, Willd. B. chinensis, Willd.;. 
Wall. Cat. 3189 (in part). B. tripartita and B. bipinnata, Wall. Cat. 
3187 (in part). 
Var. 2 bipinnata, Hook. fil. l.c. 309 ; leaves bipinnately compound, 
their segments ovate lanceolate or linear, entire lobed or toothed. 
B. bipinnata, Linn. ; Eoxb. PI. Ind. III. 411. B. chinensis, Wall. Cat. 
3189 (in part). B. Wallichii, DC. Prod. V. 598. 
Var. 3 decomposita, Hook. fil. l.c. 310; leaves deeompoundly 
pinnatifid, segments linear, slender. B. decomposita, Wall, in DC. 
Prod. V. 602, Cat. 3188 ; Clarke Comp. Ind. 141 excl. var. /3. 
In all the provinces : in waste ground near cultivation, but not 
common. — Distrib. In all warm countries. 
20. Tridax, Linn. 
A perennial herb. Leaves opposite, pinnatisect, with few narrow 
segments. Heads solitary on very long peduncles, heterogamous,. 
rayed. Ray-florets ? , fertile, ligulate or bilabiate, the outer lip large 
3-fid, the inner small and 2-fid or none. Dish-florets 4 , fertile, tubular, 
the limb elongate and 5-fid. Involucral bracts in few series, the outer 
short broad herbaceous ; receptacle flat or convex ; its scales mem- 
branous. Anthers with short acute auricles at their bases. Style-arms 
of the 4 flowers hairy above, their apices subulate. Cypselas oblong 
or depressed- globose, silky; pappus of unequal aristate feathery bristles. 
— Distrib. 7 species, tropical American, 1 being an introduced weed 
in the tropics of Asia. 
Tridax procumbens, Linn. Sp. PI. 900. Procumbent, hirsute, with 
slightly branched stems as thick as a crow-quill. Leaves membranous, 
few, ovate-lanceolate, deeply and irregularly serrate, -5 to 2 in. long. 
