38o COMPOSITAE. 



Ray-flowers yellow; leaves somewhat tomentose. A. tinctoria. 

 Ray-flowers white; leaves not tomentose. 



Leaves glabrous, ill-scented; ray-flowers neutral. A. cotula. 



Leaves pubescent, not ill-scented; ray-flowers fertile. A. arvensis. 



Anthemis tinctoria L. Perennial, herbage pubescent; stems erect, loosely 

 branched, 30-60 cm. high; leaves sessile, oblong to ovate in outline, parted in 

 narrow acute serrate lobes; heads long-peduncled, 3-4 cm. broad; ray flowers 

 yellow, pistillate; tegules oblong, obtuse, pubescent; chaff of the receptacle 

 lanceolate, acuminate; pappus crown-like. 



In fields, sparingly introduced from Europe. 



Anthemis cotula L. Dog Fennel. May-weed. Annual, much branched, 

 l)ubcruknt or glabratc, 30-60 cm. high; leaves 1—3 times pinnately-dissected 

 into thread-like lobes; heads 2 cm. broad; receptacle conical, with bristly 

 bracts near the apex, none at the margin; tegules oblong, obtuse, pubescent; 

 ray-flowers white, 10-18, becoming reflexed in age; akenes 10-ribbed, rough- 

 ened; pappus none. 



A very common weed, introduced from Europe. 



Anthemis arvensis L. Corn Chamomile. Pubescent annual herb re- 

 sembling A. cotula but not ill-scented; leaves less finely l-2-pinnatel3' parted; 

 chaff lanceolate, pointed, subtending and exceeding all the disk-flowers; akenes 

 smooth; pappus a minute border. 



Native of Europe; introduced. 



529. CHRYSANTHEMUM. 



Herbs; heads many-flowered; ray-flowers usually elongated, 

 numerous, pistillate; disk-flowers usually all fertile; involucre 

 hemispherical or flatter, the tegules more or less scarious, short- 

 appressed, imbricated in several rows; receptacle flat or convex, 

 naked; pappus none; disk-corollas often flattened or 2-winged 

 below, 4 or 5-toothed; akenes short, nearly terete, several ribbed 

 or angled, truncate at apex. 



Chrysanthemum leucanthemum pinnatifidum Lecoq. & Lemotte. Oxeye 

 Daisy. Perennial, erect, 30-60 cm. high, glabrous or nearly so, usually simple; 

 basal leaves oblong or spatulate, incisely pinnatifid or toothed; cauline smaller, 

 sessile and partly clasping, linear; heads 3-5 cm. broad, on long naked pe- 

 duncles; tegules oblong-lanceolate, obtuse, rusty at tip; ray-flowers 20-30, 

 white; akenes many-ribbed, pappus none. 



Common in fields; introduced from Europe. 



530. MATRICARIA. 



Annual or biennial glabrous branching herbs; heads many- 

 flowered, solitary or in corymbs; ray-flowers none (in ours); 

 disk-flowers yellowish-green; involucre hemispherical or flatter, 

 ot numerous more or less scarious appressed tegules in few rows; 

 receptacle conical at least in fruit, naked; pappus a minute 

 crown or none; akenes 3-5-ribbed, wingless. 



Matricaria matricarioides (Less.) Porter. Annual, 5-20 cm. high, simple 

 or branched, sparsely pubescent or glabrous; leaves oblong, 1-3 cm. long, 

 once or twice pinnately dissected into small linear acute segments; heads 5-9 



