382 THE KINDS OF PLANTS 



V. americana, Muhl. Perennial, smooth: leaflets 10-14, oblong, blunt: 

 peduncles 4-8-flowered: flowers purplish-blue, l A~ 2 A in. long. Moist soil. 



V. Cracca, Linn. Perennial, more or less pubescent, with weak stems: 

 leaflets 12-24, oblong to linear, mucronate: racemes many-flowered, 1-sided, 

 spike-like, on axillary peduncles; flowers blue to purple, M-J^ in. long. 

 Dryish soil. 



V. sativa, Linn. Spring vetch. Annual, rather pubescent, not climbing: 

 leaflets, 5-7 pairs, oblong or obovate, to linear, obtuse or retuse or mucro- 

 nate: flowers in pairs, from axils, nearly sessile, violet-purple, z A-\ in. long: 

 pod smooth, linear, 5-10-seeded. Cultivated or wild; from Europe. 



V. villosa, Roth. Hairy or winter vetch. Diffuse, very hairy: flowers 

 showy in long axillary racemes, deep purple: seeds small and black. Culti- 

 vated and escaped. Europe. Annual and biennial, perhaps sometimes 

 perennial. 



8. TRIFOLIUM. Clover. 



Annual or perennial herbs with digitate leaves of 3 leaflets (all 3 leaflets 

 joined directly to top of petiole): flowers small, with bristle-form calyx- 

 teeth, in dense heads: fruit a 1- to few-seeded little pod which does not 

 exceed the calyx. 



a. Flowers sessile in the dense heads. 

 T. pratense, Linn. Common red clover Figs. 85, 173. Erect, 

 1-2 ft., with oval or obovate leaflets, which have a pale spot 

 or band near the center and usually a notch at the end: flowers 

 rose-red, honey-sweet, the heads closely surrounded by leaves. 

 Europe, but common everywhere in the North. 



T. medium, Linn. Medium red clover. Larger, the stem less 

 straight, the leaflets oblong, entire and with a spot: head stalked 

 above the uppermost leaves. Otherwise like the last. 



T. arvense, Linn. Rabbit-foot clover. Annual; 5-10 in., 

 erect: flowers sessile in dense, cylindrical heads, which become 

 very soft and grayish fur-like, from the silky plumose calyx- 

 Trifoiium teeth; corolla insignificant, whitish. Dry, sandy soils; intro- 

 incarnatum. duced from Europe. 



aa. Flowers short-stalked in the heads. 



T. hybridum, Linn. Alsike clover. Slender, from a prostrate base, 1-3 

 ft.: leaflets obcordate: head small and globular, light rose-colored. Europe. 



T. repens, Linn. White clover. Small, the stems long-creeping and 

 sending up flowering stems 3-12 in. high: leaflets obcordate: heads small, 

 white. Common; native, also European. 



T. incarnatum, Linn. Crimson clover. Fig. 527. Stout, hairy, erect 

 plant, 1-23^ ft., with obovate-oblong leaflets and brilliant crimson flowers 

 in a long-stalked head. Europe; now frequently cultivated. 



T. refiexum, Linn. Buffalo clover. Annual or biennial, pubescent, ascend- 

 ing 8-18 in. : standard purple, keel and wings whitish : leaflets oval or obovate, 

 finely toothed. Most common in central states, from western New York. 



527. 



