394 BOTANY AND PHARMACOGNOSY. 



flowers occur in terminal heads with long peduncles, a conical 

 torus and few white pistillate ray-flowers. The flowers of culti- 

 vated plants are official (p. 554), the heads consisting mostly of 

 ligulate flowers, forming so-called " double flowers," as in the 

 cultivated chrysanthemums. 



Anacyclus Pyrethrum (Pellitory) is a perennial herb resem- 

 bling Anthemis nobilis in its general characters. The ray-flowers, 

 however, are \\'hite or purplish, and the pappus consists of a ring 

 or scale. The root is official (p. 455). 



Matricaria Chamomilla (German chamomile) is an annual, 

 diffusely branched herb, with pinnately divided leaves, consisting 

 of few, linear segments. The flowers are official (p. 553). 



Arnica montana is a perennial herb with small rhizomes; 

 nearly simple stems ; opposite, somewhat connate, entire, spat- 

 ulate, hairy leaves, and yellow flowers in large heads with long 

 peduncles. The flowers are official (p. 551). 



Arctium Lappa (Burdock) is a coarse, branched, biennial or 

 perennial herb, with alternate, broadly ovate, repand, entire, 

 tomentose, mostly cordate leaves, the basal ones being from 30 

 to 45 cm. long. The flowers are purplish-red or white, tubular 

 and form rather large corymbose heads; the involucre consists 

 of numerous lanceolate, rigid, nearly glabrous bracts, which are 

 tipped with hooked, spreading bristles. The akenes are oblong 

 and somewhat 3-angled, and the pappus consists of numerous 

 short bristles (Fig. 92). The root is official (p. 465). 



The common burdock {Arctium minus) resembles A. Lappa, 

 but is a smaller plant and is more common in the United States. 

 The heads are smaller and the inner bracts are shorter than the 

 tubular flowers, the bristles of this series being erect and with 

 the outer spreading. 



Calendula officinalis (Marigold) is an annual herb, with alter- 

 nate, spatulate, oblanceolate, entire or serrate leaves. The flowers 

 are yellow and form solitary heads, consisting of both ray and 

 tubular florets. In the cultivated varieties most of the tubular 

 florets are changed to ligulate, the latter being official (p. 555)- 



While the Compositse include a large number of genera and 

 species, the plants do not yield many important drugs, although a 

 number are used in medicine and for other purposes. 



