CLASSIFICATION OF ANGIOSPERMS. 673 



black, more or less curved pieces, which are quite mucilaginous 

 and astringent to the taste. The drug contains a gluco-alkaloid, 

 consolidin, and an alkaloid, cynoglossine. It also contains a small 

 amount of amylo-dextrin, i.e., starch which is not colored blue with 

 iodine, and tannin. The root and herb of hound's tongue 

 (Cynoglossuiu officinale) are both used in medicine. The drug 

 contains the powerful alkaloid cynoglossine, which resembles cura- 

 rine in its action ; and the gluco-alkaloid, consolidin. 



e. VERBENACE^ OR VERVAIN FAMILY.— The plants 

 are chiefly herbs or shrubs with usually opposite or verticillate 

 leaves and more or less irregular flowers (Fig. 369). 



To' this family belongs the group of verbenas, some of which 

 are used in medicine, as blue vervain (Verbena hastata), which 

 resembles eupatorium in its medicinal properties ; nettle-leaved 

 vervain (F. urticifolia), which contains a bitter glucoside. The 

 drug LiPPiA MEXICANA cousists of the leaves of Lippia dulcis 

 mexicana, and contains a volatile oil, the camphor lippiol, tannin, 

 and quercetin. Lippia citriodora, found growing in the central 

 part of South America, contains a volatile oil, of which citral is 

 a constituent. Teak-wood, which is one of the hardest and most 

 valuable of woods, is derived from the teak tree (Tecton-a 

 grandis), a large tree indigenous to Farther India and the East 

 Indies. 



/. LABIATE OR MINT FAMILY.— The plants are mostly 

 aromatic herbs or shrubs, with square stems, simple, opposite 

 leaves, bilabiate flowers, and a fruit consisting of four nutlets. 

 The calyx is persistent, regular or 2-lipped and mostly nerved. 

 The corolla is mostly 2-lipped, the upper lip being 2-lobed or 

 entire, and the lower mostly 3-lobed. The stamens are adnata 

 to the corolla tube, and are either 4 and didynamous, or 2 per- 

 fect and 2 aborted. The ovary is deeply 4-lobed (Fig. 280, /). 



The Labiatse are especially distinguished on account of the 

 volatile oils which they yield, and a few contain bitter or glucosidal 

 principles. 



I. The following plants are used in medicine: 



Scutellaria lateriflora (skullcap). The plant is a perennial 

 herb producing slender stolons somewhat resembling those of 

 43 



