FAMILIES OF FLOWERING PLANTS 145 
liar, consisting of 3 or 4 carpels which are fleshy without and hard or 
bony within. The plants have no economic and httle ornamental value. 
Family Rutaceae. Rue Family. Contains about 110 genera and 
nearly 900 species, most abundant in Australia and South Africa. They 
are trees or shrubs, rarely herbs, with strong-scented dotted herbage, 
opposite or alternate usually compound leaves, and usually cymose 
4-parted flowers, the fruit a berry or a capsule. There are many ex- 
ceptional characters, however, and the only reliable means of distin- 
guishing the rueworts from allied families is by the glandular-dotted 
foliage. 
The type of the family, Ruta, the rue, is a genus of herbs or under- 
shrubs, frequently cultivated for the powerful volatile oil which they 
Fig. 127. The southern prickly-ash (Xanthoxylum Clava-Herculis); showing fruit one-half nat- 
ural size. Original. 
contain, and which is used medicinally as a stimulant. In the same 
tribe is the highly ornamental herb Dictamnus, known as “fire-plant,” 
from the fact that the oil given off by the herbage is so volatile as 
actually to become inflammable in hot weather. 
The tribe to which Boronia belongs contains about 20 genera, ex- 
clusively Australian, many of them shrubs with pretty, heath-like flow- 
ers. Another tribe contains the prickly ash (Xanthoxylum), of which 
there are several species in the eastern United States (Fig. 127). The 
