566 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



5-celled and vary in length from 0.3 to 1 mm.; the glandular hairs 

 have a 4-celled stalk and 8-celled head, are larger and more prom- 

 inent than in S. lateriflora; and the stomata are narrowly elliptical 

 (Fig. 239). 



FIG. 239. Scutellaria lateriflora: A, portion of branch showing the ovate, 

 serrate leaves and the axillary one-sided racemes. B, lower surface of leaf 

 showing elliptical stomata. C, D, hairs from the stem and lower surface of 

 leaf. E, section of flower showing calyx (c), with crest on one side, 2-lipped 

 corolla (p), the didynamous stamens (s), and 4-locular ovary (n). F, pollen 

 grain 0.018 mm. in diameter. Hairy skullcap (Scuttellaria pilosa). G, 

 branch showing crenate leaves and helmet-shaped capsular fruits. H, 

 capsule after dehiscence showing nutlets (n). Scutellaria canescens: /, 

 view of lower surface of leaf showing numerous broadly elliptical stomata 

 and wavy cuticle. J, K, hairs from the leaf. 



Constituents. A bitter crystalline glucoside scutellarin; a 

 small quantity of volatile oil, of which little is known. 



Allied Plants. Several species of Scutellaria growing in the 

 United States are sometimes substituted for the genuine drug, 



