110 RUTACE.E. (RUE FAMILY.) 



straight, usually in fleshy albumen. Styles commonly united or cohering, 

 even when the ovaries are distinct. Fruit usually capsular. Leaves al- 

 ternate or opposite. Stipules none. — A large family, chiefly of the Old 

 World and the Southern hemisphere ; the Proper Rutace^e, represented 

 in gardens by the Rue (Ruta graveolens, L.) and Fraxinella (Dictdmnus 

 Fraxinella, L.) chiefly herbs, but the rest are shrubs or trees. — The Au- 

 kantiEjE or Orange Family, recently appended to this order, has baccate 

 fruit, seeds without albumen, and stamens sometimes almost indefinitely 

 numerous. — Our two indigenous genera are 



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. 



1. ZANTHOXYLUM, Colden. Prickly Ash. 



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

 bricated 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. (Name from £av66s, yellow, and t-v\ov, 

 wood : therefore more properly spelled with an initial X.) 



1. Z. Americ&num, Mill. (Northern Prickly Ash. Toothache- 

 tree.) Leaves and floiotrs in axillary clusters; leaflets 4-5 pairs and an odd 

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

 slender styles ; pods short-stalked. — Rocky woods and river-banks : common north- 

 ward. April, May. — A prickly shrub, with yellowish-green flowers appearing 

 before the leaves. Bark, leaves, and pods very pungent and aromatic. 



2. Z. Carolini&num, Lam. (Southern P.) Glabrous; leaflets 3-5 

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

 in a terminal cyme, appearing after the leaves ; sepals and petals 5 ; pistils 3, with 

 short styles ; pods sessile. — Sandy coast of Virginia, and southward. June. — 

 A small tree with very sharp prickles. 



2. PTELEA, L. Shrubby Trefoil. Hop-tree. 



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

 Stamens 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-foli- 

 olate leaves, and greeriish-white small flowers in compound terminal cymes. 

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



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

 places, Penn. to Wisconsin and southward. June. — A tall shrub. Fruit bit- 

 ter, used as a substitute for hops. Odor of the flowers disagreeable. 



Ailanthus olandul6sus, Desf., called Tree of Heaven, — but whose 

 blossoms, especially the staminate ones, are redolent of anything but " airs from 



