254 BOTANY AND PHAR:\IAC0GN0SY. 



The glucosidal coloring principle quercitrin is found in the 

 bark of Quercitron or black oak (Q. velutina). Q. coccifera 

 of Southern Europe yields a red coloring principle which is used 

 in dyeing. 



The wood of the American beech (Fagus americana) and of 

 the European red beech (F. sylvatica) yields a tar from which 

 on distillation the official ceosote is obtained (p. 678). 



The cork of commerce which is used for a variety of purposes 

 is derived from the bark of several species of Quercus, namely, 

 Q. Suber and 0. occidentalis growing in Spain, Southern France 

 and Algiers. 



The cotyledons of the seeds of the Beech family are rich in 

 proteids, starch and oil, and some of the nuts are dffi)le, as the 

 Spanish chestnuts obtained from Castanea vulgaris, American 

 chestnut from C. dcntata and chinquapin from C. pumila (Fig. 

 72). 



VI. ORDER URTICALES. 



This order embraces three families which, while they agree in 

 certain characters, are quite distinct in other ways. 



a. ULMACE^. OR ELM FAMILY.— The plants are trees 

 or shrubs with alternate, simple, serrate, petiolate leaves. The 

 flowers are monoecious or dioecious, with a 4- to 6-divided peri- 

 anth. The fruit is a i -seeded drupe, samara or nut. The typical 

 group of this family is that of the elms, of which the American 

 or white elm {Ulniiis americana) is the most prized for orna- 

 mental purposes. The elms )'ield valuable timber and the bark of 

 Ulmus campestris of Europe is used for tanning and dyeing be- 

 cause of the presence of tannin and a yellow coloring principle. 



The inner bark of the red or .slippery elm (Ulmus fulva) is 

 used in medicine on account of its mucilaginous character (p. 544; 

 Fig. 99, C). The tree has a gray, fragrant bark; leaves which 

 are very rough above and become fragrant on drying, and the 

 wood is reddish-brown. The samara is not hairy as in some of 

 the other species. 



b. MORACE^ OR !iIULBERRY FAMILY.— The mem- 

 bers of this family are herbs, shrubs or trees, many of them con- 

 taining a milk-juice or latex. There are many representatives in 



