368 BOTANY AND PHARMACOGNOSY. 



d. VERBENACE^ OR VERVAIN FAMILY. The plants 

 are chiefly herbs or shrubs with usually opposite or verticillate 

 leaves and more or less irregular flowers. 



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 {V. urtici folia) which contains a bitter glucoside. The 

 drug LiPPiA MEXiCANA consists of the leaves of Lippia diilcis 

 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 ( Tectona 

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

 Indies. 



e. 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 adnate 

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

 fect and 2 aborted. The ovary is deeply 4-lobed (Fig. 134, /). 



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 official: 



Scutellaria lateriflora (skullcap). The entire plant is official. 

 (See page 638.) The plant is a perennial herb producing slender 

 stolons somewhat resembling those of peppermint and spearmint. 

 The stems are erect or ascending, commonly branching and from 

 22 to 55 cm. high. 



Marrnhium vidgare (white hoarhound) is a perennial woolly 

 herb with ascending branches, the leaves and flowering tops being 

 official (p. 628). 



Salvia officinalis or garden sage is a perennial, somewhat 

 shrubby, pubescent herb. The leaves are official (p. 612). The 

 flowers are bluish, somewhat variegated, the calyx and corolla 



