FAMILIES OF FLOWERING PLANTS 



145 



liar, consisting of 3 or 4 cari^els which are fleshy without and hard or 

 bony within. The phxnts 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 onlj^ reliable means of distin- 

 guishing the rueworts from allied families is by the glandular-dotted 

 foliage. 



The type of the family, Rida, the rue, is a genus of herbs or under- 

 slirubs, frequently cultivated for the powerful volatile oil which they 



Fig. 127. The southern prickly-ash {Xanihoxylmn 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 Bictaninus, 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 prett}^ heath-like flow- 

 ers. Another tribe contains the prickly ash {Xantlioxylam), of which 

 there are several species in the eastern United States (Fig. 127). The 



