PEA FAMILY 477 



6. MELILOTUS (Tourn.) Hill. Sweet Clover, Honey Clover. 



Annual or perennial herbs, sweet-scented. Leaves alternate, pinnately tri- 

 foliolate, with toothed leaflets. Flowers perfect, in elongate lax racemes. 

 Calyx pedicelled, campanulate, teeth 5, nearly equal. Corolla yellow or white, 

 free from the filaments; banner abruptly contracted at the base, subsessile; wings 

 narrow, cohering with the short obtuse keel. Stamens 10, diadelphous; anthers 

 equal.^ Stigma terminal. Pods short and thick, straight, often subglobose, 

 indehiscent or nearly so, in ours reticulate. 



Corolla white; banner a little longer than the wings. 1, M. alba. 



Corolla yellow; banner about equalling the wings. 2. M. officinalis, 



1. M, alba Desv. Stem 1-3 m. high, erect, branched, glabrous, or puberu- 

 lent when young; leaflets obovate, oblanceolate or oblong, denticulate except at 

 the base, 1.5-2.5 cm. long, usually truncate at the apex; corolla white, 4-6 mm. 

 long. Waste places and roadsides: N.S.— D.C.— N.M.— Cahf.— Wash.; adv. 

 or nat. from Eurasia, or escaped from cultivation. My-S. 



2. M. officinalis (L.) Lam. Stem erect, 1-3 m. high, glabrous, or shghtly 

 pubescent when young; leaflets from broadly obovate to oblong, sharply denticu- 

 late, except at the base, about 2 cm, long, rounded or obtuse at the apex; raceme 

 lax and slender; corolla light yellow, 5-7 mm. long. Waste places and road- 

 sides: N.S.—Pla.— Colo.— Utah— Ida.— Mont.; adv. or nat. from Eu., or escaped 

 from cultivation. Je-S. 



7. L6tUS (Tourn.) L. Bird's-foot Trefoil. 



^ Perennial herbs, mostly with decumbent stems. Leaves alternate, odd- 

 pmnate, with foliaceous stipules. Flowers perfect, yellow, in head-like umbels; 

 banner orbicular, spreading; keel prolonged into an inciirved beak. Stamens 

 10, diadelphous; filaments dilated above; anthers equal. Pods elongate, linear, 

 usually straight, dehiscent, many-seeded. 



1. L. tenuis Waldst. & Kit. Perennial, with taproot; stem branched at the 

 base; branches slender, widely spreading, prostrate, with assurgent tips, 1.5-5 

 dm. long; leaflets 3, narrowly oblong or oblanceolate, 6-15 mm. long; flowers 

 capitate, 3-7; calyx-tube obconic; lobes linear-subulate, about as long as the 

 tube; corolla yellow, about 1 cm. long; pod 2-2.5 cm. long, 2 mm. broad. L. 

 tmuifolius (L.) Reich. L. MacbHdei A. Nels. Bottom lands: Ida.; introduced 

 from Eu. Je. 



8. ACMISPON Raf. 



Leafy-stemmed annuals. Leaves alternate, pinnately 1-5-foholate, with 

 small gland-like stipules. Flowers perfect, usually solitary, on bracted axillary 

 peduncles. Petals usually pinkish, slightly exceeding the caljrx; claws equally 

 approximate to each other; banner rounded; wings oblong; keel narrowed above 

 into a rather short acute, incurved beak, equalling or exceeding the wings. Sta- 

 mens diadelphous; filaments alternately dilated under the subequal anthers. 

 Pods linear, straight or nearly so, somewhat compressed, readily dehiscent, 

 many-seeded. 



Leaves subsessile; petiolule of the terminal leaflet ascending. i. A. americanus, 



Leaves distinctly petioled; petiolule of the terminal leaflet reflexed, or at least spreading. 



2. A. elatus. 



1. A. americanus (Xutt.) Rydb. Stem 3-5 dm. high, silky when young, 

 ttiuch branched, with strongly ascending branches; leaves 1-3-foholate; leaf- 

 lets lanceolate or linear-lanceolate, acute, silky- villous, in age glabra te, 1-2 cm. 

 long; peduncles 7-25 mm. long; bracts linear-lanceolate; calyx-teeth subulate, 

 subequal, 4 mm. long, nearly equalling the pinkish corolla. Hosackia Purshiana 

 Benth. Lotus americanus (Nutt.) Bishop. Prairies, especially in sandy soil: 

 ^linn. — Ark. — Tex.— Sonora — Ida. Plain — Submont. Je~Au. 



2. A. elatus (Nutt.) Rydb. Stem sparingly silkj^-villous, with ascending- 

 spreading branches, 3-6 dm. high; leaves 1-3-foliolate; lateral leaflets obliquely 

 oblong-lanceolate, acutish or obtuse, 1-2 cm. long, silky-villous; terminal leaf- 



