174 BOTANY. 



Fruit indehiscent, consisting of four or five drupes, arranged round a 

 common receptacle. Seeds anatropal, pendulous ; embryo exalbuminous. 

 Trees or shrubs, with exstipulate, alternate, usually compound leaves, 

 without dots. They are found in the tropical parts of America, Asia, and 

 Africa. Lindley gives ten genera and thirty-five species. Examples : 

 Simaruba, Quassia, Picrajna. All the plants of this order are intensely 

 bitter. Quassia of commerce is obtained from Quassia amara, a Surinam 

 shrub, and from Picraena excelsa, a native of the West Indies. It is 

 sometimes used illegally by brewers as a substitute for hops. 



Order 165. Zantuoxylace.e, the Zanthoxylon Family. Flowers 

 unisexual. Calyx in three, four, or five segments, with imbricated 

 sestivation. Petals the same in number, rarely 0, usually larger than the 

 calyx ; aestivation imbricated or convolute. Stamens as many, or twice as 

 many as the petals, not developed in the female flowers. Ovary consisting 

 of as many carpels as there are petals (sometimes fewer), the carpels being 

 either completely or partially united ; ovules two, rarely four, in each 

 carpel ; styles more or less combined. Fruit baccate or membranous, 

 sometimes of two to five cells, sometimes of several drupes, or two-valved 

 capsules, of which the fleshy sarcocarp is partly separable from the 

 endocarp. Seeds solitary or in pairs, pendulous; embryo lying within 

 fleshy albumen; radicle superior; cotyledons ovate, flat. Trees or shrubs, 

 svith exstipulate, alternate, or opposite leaves, having pellucid dots. They 

 exist chiefly in the tropical parts of America. Lindley enumerates 20 

 genera, including 110 species. The North American genera are Zan- 

 thoxylum, Ptelea, and Pitavia, with five species. Z. americanus, known as 

 prickly ash, or toothache tree, has an aromatic pungency in the leaves, 

 bark, and berries. 



Order 166. Rutace^, the Rue Family. Calyx having four or five 

 segments, with an imbricated aestivation. Petals alternate with the 

 divisions of the calyx, distinct, or cohering below into a spurious gamope- 

 talous corolla, rarely wanting ; aestivation either contorted or valvate. 

 Stamens equal in number to the petals, or twice or thrice as many (rarely 

 fewer by abortion or non-development), usually hypogynous, but in some 

 instances perigynous. Between the stamens and ovary there is a more or 

 less cup-shaped disk, which is either free or united to the calyx. Ovary 

 sessile or supported on a gynophore, its carpels equal to the petals in 

 number, or fewer ; ovules two, rarely four or fewer in each carpel ; styles 

 adherent above ; stigma simple or dilated. Fruit capsular, its parts either 

 combined completely or partially ; seeds solitary or in pairs, albuminous or 

 exalbuminous; embryo with a supei*>r radicle. Trees or shrubs, with 

 exstipulate, opposite, or alternate leaves, usually covered with pellucid, 

 resinous dots, and hermaphrodite flowers. The order has been sub-divided 

 into two sub-orders : 



Suh-wder 1 . Ridem^ with albuminous seeds, and the fruit, with sarcocarp 

 and endocarp combined. 



Sub-order 2. Diosmeoe^ with exalbuminous seeds and a two-valved endo- 

 carp, which dehisces at the base, and when the fruit is ripe separates from 

 174 



