RUTACE.fi. (RUE FAMILY.) 75 



2-6 pistils separate or combined into a compound ovary of as many cclls s 

 raised on a prolongation of the receptacle (gynophore') or glandular disk. 

 Embryo large, curved or straight, usually in fleshy albumen. Styles com- 

 monly united or cohering, even when the ovaries are distinct. Fruit usu- 

 ally capsular. Leaves alternate or opposite. Stipules none. A large 

 family, chiefly of the Old World and the Southern hemisphere ; the Proper 

 Rutacece, represented in gardens by the Rue (Ruta graveolens, Z.), are 

 mostly herbs ; while our two genera, of trees or shrubs, belong to what 

 has been called the order Zanthoxylacece, but are not distinct from the 

 Diosmece. 



1. ZANTIIOXYLUM, Golden. 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 Avith the 

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

 Pods thick and fleshy, 2-valved when ripe, 1 - 2-seeded. Seed-coat cmstaccous, 

 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 av&os, yellow, and vAo>, 

 wood.) 



1. 5K. Americamim, Mill. (NORTHERN PRICKLY ASH. TOOTH- 

 ACHE-TREE.) Leaves and flowers 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; com- 

 mon northward. April, May. A prickly shrub, with yellowish-green flowers 

 appearing with the leaves. Bark, leaves, and pods very pungent and aromatic. 



2. Z. Caroliiifaniim, Lam. (SOUTHERN PRICKLY ASH.) Glabrous; 

 leaflets 3 -5 pairs and an odd one, ovate or ovate-lanceolate, oblique, shining 

 abom ; 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 south- 

 ward. June. A small tree, with very sharp prickles. 



2. PTEL.EA, 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-cclled 

 and 2-sccded samara, winged all round, nearly orbicular. Shrubs, with 3-foli- 

 olate leaves, and greenish-white small flowers in compound tormina! cymes, 

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



1. P. tlifoliata, L. Leaflets ovate, pointed, downy when young. 

 Rocky places, Penn. to Wisconsin and southward. June. A tall shrub. Fruit 

 bitter, used as a substitute for hops. Odor of the flowers disagreeable ; but not 

 BO much so as those of the 



AILANTHUS GLANDUL6sus, or TREE-OF-HEAVEN, a cultivated tree allied 

 to this family, whose flowers, especially the staminate ones, redolent of any- 



