Flora of the Malayan Peninsula. 25 



Cypselas not beaked ; leaves opposite, simple to 

 pinnatisect . . . . . . . . 19. Bidens. 



Pappus of membranous scales ; heads radiate ; leaves 

 opposite : — 



Scales of pappus feathery, fringed ; heads medium- 

 sized . . . . . , . . . . 20. Tridax. 



Anthers inappendiculate at the apex ; receptacle (in our 

 species) not paleaceous ; pappus absent or reduced to a 

 raised rim, rarely scaly and short ; leaves usually alter- 

 nate {Anthemide(c) : — 

 Flower-heads discoid, heterogamous ; pappus absent : — 

 Florets of the circumference very numerous ; cypselas 

 flat or concave at the top ; flower-heads globose or 

 hemispheric, sub-sessile ; bracts of involucre in 2 series, 

 spreading in fruit . . . . . . . . 21. Centipeda. 



Florets of the circumference few ; heads very small, in 

 racemes or panicles ; cypselas ellipsoid or obovoid, 

 rounded at the apex .. .. ..22. Aktemisia. 



Corollas of all the florets flatly expanded from a tubular base, 

 ligulate, their apices 5-toothed ; leaves radical or cauline and 

 alternate, never opposite ; stem always herbaceous, fistulose ; 

 sap milky (Ciclioriece) : — 



Pappus of simple hair-like bristles, at least in the central 

 florets ; florets yellow, cypselas fusiform or oblong, with 

 glabrous or puberulous ribs . . . . . . 23. Ceepis. 



Note. — The above key is taken mainly from "Bengal Plants," by Lieut. -Col. D. 

 Prain, F.E.S., Superintendent, Royal Botanic Garden, Calcutta. 



1. Veenonia, Schreb. 

 Herbs, shrubs, climbers or small trees. Leaves alternate, penni- 

 nerved, entire or dentate. Heads axillary or terminal, solitary or in 

 cymes or panicles, homogamous ; flowers often few, but very rarely 

 solitary. Involucre ovoid, globose or hemispheric, as long as or shorter 

 than the flowers ; bracts in many series, the inner longest. Receptacle 

 naked or pitted, sometimes with short hairs. Corollas all equal, tubular, 

 slender ; lobes 5, narrow. Anther-hases obtuse, sagittate. Style-arms 

 subulate, acute, hairy. Cypselas striate, ribbed or angled, rarely terete, 

 truncate at the apex ; pappus of many hairs, usually in two rows, the 

 inner hairs thin and slender, the outer sometimes stout and com- 

 pressed, persistent or deciduous. — Distrib. About 500 species, mostly 

 American. 



A large shrub or small tree ; leaves sub-coriaceous ; involucral bracts 



obtuse . . . . . . . . . . . . 1. T'. arborea. 



Herbaceous annuals ; leaves membranous ; involucral bracts acumi- 

 nate : — 

 Heads few, 35 in. in diam., in long-peduncled cymes. . .. 2. V. chinensis. 



235 



