138 KEY AND FLORA 



1. A. caryocarpus Ker. GROUND PLUM, BUFFALO APPLE. Covered 

 with pale, close-lying down. Leaflets narrow, oblong. Flowers violet- 

 purple, in a short, narrow raceme. Fruit looking like a small, green, 

 pointed plum, about f in. in diameter, eatable. N.W., and S. to 

 Texas. 



2. A. mexicanus A. DC. PRAIRIE APPLE. Smooth or with some 

 loose hairs. Corolla cream color, with the tip bluish. Fruit globular, 

 not pointed, eatable. Prairies, Illinois and S.W. 



3. A. canadensis L. Erect, often tall (1-4 ft. high), more or less 

 downy. Leaflets oblong, 21-27. Flowers pale greenish, in long 

 spikes. Pod dry, 2-celled, sessile. River bottoms, prairies, and woods. 



4. A. parviflorus MacM. Erect and slender, finely downy, some- 

 what ash-color, 1-2 ft. high. Leaflets 1121, linear, obtuse, distant. 

 Flowers purple, ^ l s in. long, in long, slender racemes. Pods sessile, 

 in. or less in length, concave on the back, white-hairy, becoming 

 smooth. Prairies, especially N.W. 



XX. DESMODIUM Desv. (MEIBOMIA) 



Perennial herbs. Leaves pinnate, with stipules, usually 

 with 3 leaflets. Flowers in axillary or terminal racemes, or 

 sometimes ; .u panicles, usually purple, sometimes pink or 

 whitish. Calyx usually somewhat 2-lipped. Standard ovate, 

 obovate, or roundish ; wings attached to the straight or nearly 

 straight keel by a little appendage projecting from each side 

 of the keel. Stamens monadelphous (9 and 1) or all united at 

 their bases. Pod flat, its lower margin variously lobed, sepa- 

 rating into flat segments which are usually furnished with 

 short, strong, hooked hairs, making the fruit a troublesome 

 bur. [A large and rather difficult genus. Most of the species 

 can only be distinguished by the fruit, which matures in late 

 summer or autumn.] 



XXI. VICIA L. 



Climbing or spreading herbs. Leaves odd-pinnate, usually 

 ending in a tendril. Leaflets many, entire or toothed at the 

 tip ; stipules half arrow-shaped. Flowers blue, purple, or yel- 

 low, in axillary racemes. Calyx teeth nearly equal. Wings 

 united to the keel. Stamens diadelphous (9 and 1) ; filaments 

 thread-shaped ; anthers all alike. Style bent, smooth or downy 

 all round or bearded below the stigma ; ovules usually many. 

 Pod flattened, 2-several-seeded. Seeds globular. 



