RUTACEAB (RUB FAMILY) , 537 



RUTACEAE (Rue Family) 



Plants with simple or compound leaves, dotted with pellucid glands and 

 abounding with a pungent or bitter-aromatic acrid volatile oil, producing hypogy- 

 nuus almost always regular 3-5-merous flowers, the stamens as many or twice 

 as many as the sepals {rarely more numerous) ; the 2-6 pistils separate or com- 

 bined into a compound ovary of as many cells, raised on a prolongation of the 

 receptacle (gynophore) or glandular disk. Embryo large, usually in fleshy 

 albumen. Styles commonly united or cohering. Fruit usually capsular. Leaves 

 in ours alternate. Stipules none. — A large family, chiefly of the Old World 

 and the southern hemisphere. 



1. Zanthoxylum. Flowers dioecious ; ovaries 3-5, separate, forming fleshy pods. 



2. Ptelea. Flowers polygamous ; ovary 2-celled, forming a samara, like that of Elm. 

 8. Ruta. Flowers perfect ; ovary 4-5-lobed, forming a several-seeded capsule. 



1. ZANTH6XYLUM L. Pkiokly Ash 



Flowers dioecious. Sepals 4 or 5, obsolete in one species. Petals 4 or 5, 

 imbricated in the bud. Stamens 4 or 5 in the sterile flowers, alternate with the 

 petals. Pistils 2-5, separate, but their styles conniving or slightly united. Pods 

 thick and fleshy, 2-valved, 1-2-seeded. Seed-coat crustaceous, black, smooth 

 and shining. Embryo straight, with broad cotyledons. — Shrubs or trees, with 

 mostly pinnate leaves, the stems and often the leafstalks prickly. Flowers small, 

 greenish or whitish. (From ^ai/dSi, yellow, and ^liXop, wood.) 



1. Z. americanum Mill. (Northern P., Toothache-tree.) Leaves and 

 flowers in sessile axillary umbellate clusters ; leaflets 2-4 pairs and an odd one, 

 ovate-oblong, downy when young; calyx none; petals 4-5; pistils 3-5, with 

 slender styles; pods short-stalked. {Xanthuxylum of auth.). — Rocky woods 

 and river-banks, w. Que. to Minn., s. to Va., Ky., Mo., and e. Kan. Apr, May. 

 — An aromatic shrub, with yellowish-green flowers appearing before the leaves. 



2. Z. C14va-H6rculis L. (Southern P.) Glabrous; leaflets 3-8 pairs and 

 an odd one, ovate or ovate-lanceolate, oblique, shining above ; flowers in an 

 ample terminal cyme ; sepals and petals 5 ; pistils 2-3, with short styles ; pods 

 sessile. (Z. carolinianum Lam.) — Sandy coast of Va., and southw. June. — 

 A small tree with very sharp prickles. 



2. PTELEA L. Shkdbby Trefoil. Hop Tree 



Flowers polygamous. Sepals 3-5. Petals 3-5, imbricated in the bud. Sta- 

 mens as many. Ovary 2-celled ; style short ; stigmas 2. Fruit a 2-celled and 

 2-seeded samara, winged all round, nearly orbicular. — Shrubs, with 3-foliolate 

 leaves, and greenish-white small flowers in compound terminal cymes. (The 

 Greek name of the Elm, here applied to a genus with similar fruit.) 



1. P. trifolijlta L. Leaflets ovate, pointed, downy when young. — Rocky 

 places, L. I. to Out., Minn., and southw. ; cultivated and often established else- 

 where. June. — A tall shrub. Fruit bitter, used as a substitute for hops. Odor 

 of the flowers disagreeable. 



Var. m611is T. & G. Branohlets, petioles, and both surfaces of the somewhat 

 thickish leaflets densely and permanently velvety. — Shore of L. Mich., Sauga- 

 tuck, Mich. {Wheeler); also Tex., etc. 



3. RtTTA [Tourn.] L. Rue 



Flowers perfect, 4-5-merous. Calyx: persistent. Petals yellow, the sides 

 and apex strongly inroUed, the margin denticulate or oiliate-dentate. Stamens 

 8-10, inserted about the base of the torus, the alternate ones smaller. Capsule 

 4-^-lobed, dehiscent at the sumniit, many-seeded. — Heavy-scented herbs ox 



