RUTACEAE. 58 1 



Family 5. RUTACEAE Juss. 

 Rue Family. 



Trees or shrubs, rarely herbs, with heavy-scented and glandular- 

 punctate foliage, mainly compound exstipulate leaves, and (in our 

 species) polygamo-dioecious generally cymose flowers. Sepals 4 or 5, or 

 none. Petals 4 or 5, hypogynous or perigynous. Stamens of the same 

 number, or twice as many, distinct, inserted on the receptacle ; anthers 

 2-celled, mostly versatile. Disk annular. Pistils 2-5, distinct, or 1 and 

 compound of 2-5 carpels, inserted on the receptacle. Fruit (in our 

 species) a capsule, or samara. Seeds oblong or reniform ; endosperm 

 generally fleshy, sometimes none. About no genera and 880 species, 

 most abundant in South Africa and Australia. 



Pistils 2-5, distinct; fruit fleshy, capsular. 1. Xanthoxylutn. 



Pistil 1, 2-celled; fruit a samara. 2. Ptelea. 



1. XANTHOXYLUM L. 



Trees or shrubs with alternate odd-pinnate leaves, the twigs and petioles com- 

 monly prickly. Flowers axillary or terminal, cymose, whitish or greenish, mostly 

 small. Sepals 4 or 5. or none. Petals imbricated. Staminate flowers with 4 or 5 

 hypogynous stamens. Pistillate flowers with 2-5 distinct pistils, rarely with some 

 stamens. Carpels 2-ovuled. Pods 2-valved, 1-2-seeded. Seeds oblong, black 

 and shining. [Greek, yellow-wood.] About no species, of temperate and tropical 

 regions. In addition to the following, 2 others occur in the Southern States. 



Flowers in small sessile axillary cymes; calyx none. 1. X. Americanutn. 



Flowers in large terminal compound cymes; calyx present. 2. X. Clava-Herculis. 



i. Xanthoxylum Americanum Mill. Prickly Ash. Toothache-tree. 

 (I. F. f. 2269.) A shrub, or small tree. Leaves pubescent when young, glabrous 

 or nearly so when old; leaflets 5-1 1, ovate, opposite, dark green above, lighter be- 

 neath, 3-5 cm. long, crenulate or entire, acutish; flowers greenish, about 3 mm. 

 broad, borne on the wood of the previous season and appearing before the leaves; 

 pistils 2-5; capsules black, ellipsoid, about 4 mm. long, short-stiped, 1-2-seeded. 

 In woods and thickets, Quebec to Va., S. Dak., Neb. and Kans. April-May. 



2. Xanthoxylum Clava-Herculis L. Southern Prickly Ash. Sea Ash. 

 Pepper-wood. (I. F. f. 2270.) A small, very prickly tree, the prickles sup- 

 ported on cushions of cork sometimes 2 dm. broad. Leaves glabrous, shining 

 above, dull beneath; leaflets 5-17, obliquely ovate, 3-7.5 cm. long, acute, cren- 

 ulate; flowers greenish white, appearing before the leaves; pistils 2 or 3; capsules 

 about 4 mm. long, sessile. Along streams, Va. to Fla., Ark. and Tex. June. 



2. PTELEA L. 



Shrubs or small trees, without prickles, the bark bitter. Leaves 3-5-foliolaU ; 

 flowers greenish white, polygamous, corymbose-paniculate; calyx 4-5-parted, the 

 lobes imbricated; petals 4 or 5, much longer than the calyx, also imbricated; sta- 

 mens 4 or 5. alternate with the petals; filaments hairy on the inner side, present 

 in the pistillate flowers but the anthers abortive or wanting; ovary flattened, 2-celled 

 (rarely 3-celled); fruit nearly orbicular, 2-winged (rarely 3-winged), indehiscent: 

 cells i-seeded; seed oblong-ovoid. [Greek, Elm.] About 6 species, natives of the 

 U. S. and Mex. 



1. Ptelea trifoliata L. Three-leaved Hop-tree. Shrubby Trefoil. 

 (I. F. f. 2271.) A shrub or small tree. Leaves 3 -foliolate, pubescent when young, 

 glabrate when old; leaflets 5-12 cm. long; crenulate; flowers about I cm. broad; 

 odor disagreeable; sepals 1 mm. long, obtuse; petals about 6 mm. long, oblong; 

 samara 1.6-1.8 cm. in diameter, the wing membranous and reticulated, emargin- 

 ate. In woods, Conn, to Fla., S. Out., Minn., Kans. and Tex. June. 



