134 XANTHOXYLACEiE. Ptelea. 



A shrub 6-8 feet high, pubescent when young. Petioles about 2 inches long. Leaflets 

 2-4 inches long, obscurely crenate-scrrate, more or less pubescent beneath. Flowers lateral 

 and terminal ; the odor disagreeable. Samara three-fourths of an inch in diameter. 



On the shore of Lake Erie, near Presque Isle {Nuttall), and probably also within the Umits 

 of New- York Stale. New-York to Carolina {Pursh). Fl. June. Tonic and aromatic. It 

 is said to be good for worms, and to cure inlermittcnts. The fruit has likewise been used as 

 a substitute for hops. 



Group 9. Ovary compound, 2 - 3-lobed, 2 - 3-celled, free from the calyx. Petals 

 usually one fewer than the sepals, or sometimes tcanting. Stamens definite, 

 distinct, inserted on or around a hypogynous disk. Seeds destitute of albumen. 

 — Mostly trees or shrubs. 



Order XXXI. ACERACEiE. Juss. The Maple Tribe. 



Calyx of 5 (rarely 6 — 9) more or less united sepals, colored : sestlvation im- 

 bricated. Petals as many as the sepals and alternate with them, inserted round 

 a hypogynous disk ; sometimes none. Stamens usually 8 (sometimes 3 - 12), 

 distinct, inserted on the disk. Ovary 2-lobed, composed of 2 united carpels, 

 each containing 2 collateral ovules. Styles between the lobes of the ovary, 

 more or less united, stigmatose on the inside. Fruit composed of 2 samaroid 

 indehiscent carpels, each usually perfecting but a single seed, finally separating 

 from the short filiform axis. Seeds with little or no albmnen. Embryo curved 

 or conduplicate, with wrinkled foliaceous cotyledons irregularly folded. — 

 Trees or shrubs, with opposite palmately lobed or pinnately 3 — 6-foliolate 

 leaves and no stipules. Flowers small, regular, by abortion often polygamous, 

 in racemes, corymbs or fascicles ; often preceding the leaves. 



1. ACER. Mcench. ; Endl. gen. 5558. MAPLE. 



[ From the Latin, acer, sharp or hard ; on account of the hardness of the wood, which was employed for making 



spears, etc.] 



Flowers mostly polygamous. Petals colored like the sepals, often wanting. Stamens 7-10, 

 rarely 5. — Leaves simple. The sap in many species contains sugar. 



