c OMPOSIT^:. 



Heads scattered or solitary; 

 terminating leafy branches or peduncles; 



Receptacle bristly ANTHEMIS 56 



naked; 



conic or f asiform MATBICABIA 58 



44 n 5 heads radiate ...CHRYSANTHEMUM 59 



discoid COTUL A 61 



sessile in the forks SOLIVA 60 



Heads cymose-corymbose; 



small; flowers white .. ACHILLKA 57 



larger; flowers yellow TANACETUM 62 



Heads panicled, small, rayless. nodding ARTEMISIA 63 



56. AXTHEMIS, Diosc. Herbs with pinnately dissected leaves, and 

 rather large heads on peduncles terminating leafy branches. Involucre 

 hemispherical. Ray -flowers -white; disk-flowers yellow. Chaff of recep- 

 tacle bristly. Achenes not flattened, glabrous; the truncate summit 

 with or without a short coroniform pappus. 



1. A. COTULA, L. (MAYWEED). Strong-scented annual weed 1 2 ft. 

 high, somewhat freely branching: receptacle conical, destitute of chaff 

 near the margin: achenes 10-ribbed, rugose or tuberculate. In waste 

 grounds. July Oct. 



57. ACHILLEA, Diosc. Erect perennial herb, with pinnately mul- 

 tifid lanceolate leaves, and small heads in a dense terminal cymose 

 corymb. Chaff of receptacle membranaceous. Rays few, short and 

 broad. Achenes obcompressed, callous-margined, glabrous, destitute of 

 pappus. 



1. A. Millefolium, L. (YARROW). Stoutish, 12 ft. high, villous- 

 lanate to nearly glabrous: heads crowded in a fastigiate flat-topped 

 cyme: involucre oblong; rays 4 or 5, white. Very common in sandy 

 soils toward the sea. 



58. M4TRICARIA, Tourn. Our species annual herbs, with finely 

 dissected sweet-scented foliage and rayless heads of green flowers ter- 

 minating the branches. Receptacle conical or ovoid, naked. Achenes 

 glabrous, 3 5-nerved on the sides, rounded on the back, nearly desti- 

 tute of pappus. 



1. M. discoidea, DO. Low often diffusely branching, mostly less than 

 1 ft. high, sweet-scented: heads sbort-peduncled: bracts of involucre 

 broadly oval, scarious, with green centre, not half the length of the 

 ovoid disk: achenes oblong, somewhat angled, with an obscure coroni- 

 form margin at summit. By waysides everywhere, mostly in hard 

 sterile soil. April, May. 



2. M. occidentalis, Greene. Erect, very stout, \Y Z 2% ft. high, 

 corymbosely branched at summit, the herbage nearly scentless: heads 

 more than twice as large as in the last and 68 lines high: receptacle 



