CLASSIFICATION OF ANGIOSPERMS. 319 



b. BUXACE^ OR BOX TREE FAMILY.— The plants are 

 shrubs with alternate or opposite, evergreen leaves, and usually 

 axillary monoecious or dioecious flowers. The most important 

 plant of this family is the Box tree {Buxus senipervirens) which 

 is extensively cultivated. The wood is used for making musical 

 instruments and for other purposes, and the twigs have been used 

 in medicine. The latter contain several alkaloids, the most impor- 

 tant being buxine which resembles beberine ; a volatile oil con- 

 taining butyric acid and a wax containing myricyl alcohol and 

 myricin. 



c. ANACARDIACE^ OR SUMAC FAMILY.— The plants 

 are trees or shrubs with an acrid, resinous or milky latex, and 

 alternate leaves. 



Rhus radicans, Poison Ivy or Poison Oak, is a woody vine, 

 climbing by means of aerial roots and sometimes becoming quite 

 shrub-like, which is common along roadsides in the United States. 

 The leaves are 3-foliate, the leaflets being ovate, acuminate, nearly 

 entire, inequilateral and with short stalks ; the flowers are green 

 and in loose axillary panicles ; the fruit is a globular, glabrous, 

 grayish drupe (Fig. 163, D, E). The poisonous properties of this 

 plant are due to a fixed oil known as toxicodendrol, a principle 

 somewhat resembling the vesicating principle cardol found in the 

 Cashew Nut. The latter is the fruit of Anacardinm occidentale, 

 a shrub growing in tropical America. A principle resembling 

 cardol is found in the East India Marking tree or Ink tree (Seme- 

 carpus Anacardinm) and Holigarna ferruginea of India. 



The Poison Sumac or Poison Elder {Rhus vernix) is a 

 shrub or small tree found in swamps in the United States and 

 Canada. The leaves are 7- to 1 3-foliate, with obovate or oval, 

 acuminate, entire leaflets ; the flowers are small, green, and in 

 axillary panicles; the fruit resembles that of R. radicans (Fig. 

 163, A, B, C). The plant is poisonous like R. radicans and prob- 

 ably contains the same principle. Other species of Rhus are also 

 poisonous, as the western Poison Oak {R. diversiloba) of the 

 Pacific Coast, and the Japanese Lacquer or Varnish tree {R. ver- 

 nicifera and R. succedanea) . The lacquer trees grow wild in 

 both China and" Japan where they are also cultivated. The lac 

 is obtained by incising the bark and removing it with a pointed 



