Bidens.] COMPOSITE. 211 



2. B. tripartita, L. ; leaves petioled simple or 3-cleft, heads suberect. 

 Watery places from Isla and Elgin southd. ; Ireland ; Channel Islands ; fl. 

 July-Sept. — Habit of B. cernua, but more slender ; leaves often 3-partite ; 

 heads smaller; outer invol. bracts narrower, inner acute, and pappus- 

 bristles 2 shorter. — A Thames form (Putney) has broader heads, more 

 numerous florets and 3-4 pappus-bristles.— Distrib. Europe (Arctic), N. 

 Africa, W. Asia to India, N. America. 



11*. GALIN'SO'GA, Ruiz and Pavon. 



Annual trichotomously branched herbs. Leaves opposite, triple-nerved, 

 serrate. Floioer-heads small, yellow, rayed ; invol. bracts 1-seriate, margins 

 scarious ; receptacle conical, with lanceolate scales under each flower. 

 Ray-fl. female ; tube short, pubescent ; ligule very broad, short, 3-fid ; 

 style-arms linear, obtuse. Disk-fl. tubular, 2-sexual, 5-toothed ; anthers 

 short, with a short terminal appendage, cells shortly tailed. Fruit hispid ; 

 pappus of 1 series of ciliate scales. — Distrib. S. America; species 5. — ■ 

 Etym. M. de Galinsoga, a Spanish botanist. 



G. parviflo'ra, Cav. ; leaves ovate obtusely-serrate ciliate. 

 Cultivated fields and roadsides; chiefly in Surrey and Middlesex; introd. from 

 Peru ; fl. July-Oct. — More or less pubescent. Stem 1-2 ft., slender. Leaves 

 1-2 in., shortly petioled. Heads in dichotomous cymes, £-j in. diam. ; 

 peduncle ebracteate, glandular ; involucre hemispherical ; bracts unequal 

 oblong, ciliate. Ray-fl. 4-6. Fruit obovoid, compressed, black; pappus 

 scales 10-15, narrow-oblong. — Distrib. Trop. S. America. 



12. AN'THEMIS, L. 



Herbs, sometimes shrubby below, strong-scented. Leaves alternate, 

 2-pinnatifid. Heads solitary, yellow, with (rarely without) a broad white 

 ray ; invol. bracts imbricate, in few series ; receptacle fiat or conic ; scales 

 membranous, slender. Ray-fl. 1-seriate, ligulate, female or neuter ; style- 

 arms short, edges thickened, tips obtuse papillose. Disk-fl. tubular, 

 2-sexual, 5-toothed ; anther-cells not tailed ; style-arms as in the female. 

 Fruit subterete, grooved or striate, crowned with a tumid disk ; pappus 0, 

 or a short membrane. — Distrib. Europe, N. Africa, W. Asia ; species 

 about 60. —Etym. The old Greek name. 



1. A. arven'sis, L. ; annual, scales of receptacle mucronate longer than 

 the flattened disk-fi., ray-fl. female white. Corn Chamomile. 

 Fields and waste places, local, from Caithness southd. ; S. and E. Ireland ; 

 Channel Islands; (a colonist, Wats.) ; fl. June-Aug.— Pubescent or hoary. 

 Stem 1-2 ft., usually erect from a decumbent base, branched. Leaf-segments 

 &-2 in., linear, acute, not dotted. Heads 1-1^ in. broad ; peduncle rather 

 long, slightly swollen upwards ; invol. bracts scarious, pale, obtuse, inner 

 lacerate. Fruit glabrous, subequally ribbed all round, truncate ; disk 

 broad, crenulate. — Distrib. Europe, N. Africa, W. Asia; introd. in N. 

 America. 



P 2 



