COMPOSITACEAE (COMPOSITE FAMILY) 231 



BB. Rays 10-20; pappus none; akenes oblong, faintly 3-s-ribbed; herbage sweet- 

 scented. W. E. — Medicinal plant. M. chamomille (garden camomile) 

 AA. Heads rayless. W. C. E. M. suaveolens (pineapple weed} 



CHRYSANTHEMUM (Chrysanthemum) 



Perennial. Leaves alternate, incised or dissected. Heads large. Ray 

 flowers white. Disk flowers yellow; — (Gk. chrysos = gold, anthos = a 

 flower ; some species outside our range even have yellow rays.) 



A. Heads 1-2 cm. wide, many, corymbose; rays 10-20, about twice as long as wide; 



pappus a toothed crown. E. C. parthenium (feverfew) 



AA. Heads 2.5-5 cm. wide, few, terminal; rays 20-30, 4 or more times as long as 



wide; pappus none. W. — A very bad meadow weed. 



C. leucanthemum (ox-eye daisy) 



COTULA 



Leaves alternate. Heads many-flowered, with 2 kinds of flowers; re- 

 ceptacle naked. Outer flowers pistillate, in 1-3 rows, apetalous. Iimer 

 flowers 4-toothed, yellow, perfect. Pappus none or a mere ring. — (Gk. 

 kotula = a small cup, referring to the hoUow at the base of the clasping 

 leaves.) 



A. Herbage glabrous or very nearly so. W. 



C. coronoplfolia (salt-marsh butterhead) 

 AA. Herbage pubescent. W. ^ C. australis 



TANACETUM (Tansy) 



Perennial, aromatic. Leaves alternate, entire to dissected. Heads with 

 I or 2 kinds of flowers ; receptacle naked. Pappus none or crownlike. — 

 (Said to be from Gk. athanatox = immortal ; referring to the durable flowers.) 



A. Leaves 2-s-lobed or parted, but some of the leaves -may be entire. 



B. Leaf lobes linear. E. T. capitatum 

 BB. Leaf lobes not linear or none of the leaves lobed. E. T. nuttallil 



AA. Leaves pinnately-parted or -dissected into many segments. 



C. Herbage quite pubescent. 



D. Herbage silky with white hairs; heads many, 6-8 mm, wide. E. 



T. potentilloides 

 DD. Herbage villous-pubescent; heads 1-8, 12-16 mm. wide. W. 



T. huronense (seashore tansy) 



CC. Herbage glabrous or very nearly so; heads many, 6-10 mm. wide. W. — 



Medicinal plant. T. vulgare (garden tansy) 



ARTEMISIA (Sagebrush) 



Herbs or shrubs, annual or perennial, bitter, aromatic. Leaves alternate. 

 Heads rayless, small ; flowers of i or 2 kinds, white or yellowish ; receptacle- 

 naked or woolly. Outer flowers pistillate and inner perfect, or all perfect. 

 Pappus none. — (Honor of Artemisia, the wife of Maugolus.) 



