FABACEAE 607 



tube campanulate ; lobes lanceolate to linear-lanceolate, longer than the tube : corolla 

 white, pink or tinged with purple ; standard acute, surpassing the wing-petals. 



In sandy soil or waste places, or on rocks, Pennsylvania to Florida and Texas. Spring to fall. 



10. Trifolium amphiinthum T. & G. Perennial, stoloniferous, glabrous or nearly 

 so. Stems branched at the base, the branches prostrate, creeping, 2-16 cm. long, simple 

 or branched : leaves clustered at the nodes : leaflets 3, the blades broadly cuneate-obovate, 

 5-10 mm. long, emarginate, undulate or denticulate : peduncles overtopping the leaves, 

 slender : heads rather few-flowered : calyx nerved ; tube campanulate ; lobes lanceolate or 

 subulate-lanceolate, about as long as the tube : corolla bright purple, 8-10 mm. long ; 

 standard somewhat longer than the wing-petals : pods mainly solitary from fertile flowers 

 usually borne at the lower nodes. 



On prairies, Louisiana and Texas. Spring. 



11. Trifolium saxicola Small. Perennial, glabrous. Stems branclied at the base, 

 the branches prostrate, creeping, 0.5-2 dm. long, rigid : leaflets 3, the blades cuneate or 

 obdeltoid, 3-8 mm. long, lirm, usually truncate or retuse at the apex, spiny-serrate ; 

 secondary nerves close, straight : peduncles stout, surpassing the subtending leaves : calyx 

 glabrous,' about 3 mm. long ; tube narrowly campanulate, prominently ribbed ; lobes subu- 

 late-lanceolate, shorter than the tube : corolla white, 5-7 mm. long ; standard arose at the 

 apex, surpassing the wing-petals. 



On granite rocks, Stone Mountain, Georgia. Summer. 



12. Trifolium ripens L. Perennial, glabrous or sparingly pubescent. Stems more 

 or less densely branched at the base, the branches prostate, creeping, 1-4 dm. long : leaf- 

 lets 3, the blades obovate or orbicular-obovate or oval, 1-1.5 cm. long, rounded or notched 

 at the apex, denticulate : peduncles elongated, erect or ascending, 5-20 cm. long : calyx 

 glabrous ; tube campanulate, ribbed ; lobes lanceolate or at maturity triangular-lanceolate, 

 shorter than the tube : corolla usually white, 6-10 mm. long ; standard much longer than 

 the wing-petals and the keel. 



In all situations, throughout North America except the extreme north and south. Naturalized, 

 wholly or perhaps only partially from Europe. Widely distributed. Spring to winter. 



13. Trifolium hybridum L. Perennial, glabrous or nearly so. Stems branched at 

 the liase, the branches erect or ascending or spreading, 2-8 dm. long, more or less 

 branched : leaflets 3, the blades oval to oblong varying to ovate or obovate, or sometimes 

 suborbicular, rounded or notched at the apex, denticulate, the teeth often spine-like : 

 peduncles usually surpassing the subtending leaves : heads rather dense : calyx often 

 sparingly pubescent ; tube campanulate ; lobes subulate-lanceolate, surpassing the tube in 

 length : corolla pink or rarely nearly white : standard longer than the wing-petals. 



In various situations, Nova Scotia to Idaho, Georgia and Missouri. Spring to fall. 



10. LOTUS L. 



Annual or perennial herbs or shrubs, with glabrous or silky-pubescent foliage. Leaves 



alternate : blades 1-foliolate or pinnately 3-foliolate, petioled : leaflets with entire blades. 



Flowers perfect, solitary in the axils or clustered. Calyx pedicelled : lobes nearly equal, 



often shorter than the tube. Corolla yellow, white or reddish : standard broad, clawed : 



wings narrow, about as long as the incurved obtuse keel. Stamens 10, diadelphous 



(9 audi): filament opposite the standard free. Anthers all alike. Ovary sessile. Style 



glabrous, incurved or inflexed. Ovules 1 or several. Pod narrow, flattish or nearly 



terete, 2-valved, straight or curved. Seeds 1 or several. IHosackia Dougl.] 



Stem leaves persistent : leaflets oblong to ovate : branches villous. 1. L. Americana. 



Stem leaves fugacious : leaflets linear : branches glabrous or glabrate. 2. L. Helleri. 



1. Lotus Atnericanus (Nutt. ) Bisch. Foliage more or less densely villous or 

 glabrate. vStems 2-6 dm. tall, branching : leaves 3-foliolate, or tlie upper .sometimes 1-folio- 

 late, the lower with short petioles, the upper sessile : leaflets mostly 3, the blades oblong or 

 elliptic varying to lanceolate, 0.8-2.5 cm. long, acute or sharply acuminate, inequilateral: 

 peduncles 1-flowered, bearing a bractlet at the top : calyx copiously pubescent ; tube 

 turbinate ; lobes narrowly linear, over twice as long as the tube : corolla 6-7 mm. long, 

 pink ; standard striped with purple : pods linear, 2.5-3 cm. long, straight, acute. 



In dry soil, Minnesota to Texas and New Mexico. Summer. 



2. Lotus H611eri Britton. Foliage glabrous or finely pubescent. Stems 2-6 dm. 

 tall, usually much and regularly branched : leaves 3-foliolate or the upper ones 1-foliolate : 

 leaflets mostly 3, the blades linear or linear-oblong, 5-15 mm. long, acute: peduncles 



