54 2 FLORA. 



i. Lotus corniculatus L. Bird's-foot Trefoil. Ground Honeysuckle. 

 Bloom-fell (I. F. f. 2084.) Perennial, appressed-pubescent or glabrate. Stems 

 decumbent or ascending, 7 cm. -6 dm. long; leaves 3-foliolate, short-petioled; leaf- 

 lets obovate, oblanceolate or oblong, 7-17 mm. long; stipules similar to the leaf- 

 lets, often as large; peduncles sometimes 10-13 cm - l° n g> 3-12-flowered; calyx- 

 lobes acute, as long as the tube, or shorter; corolla bright yellow, 12-20 mm. long, 

 or the standard reddish; pods linear, spreading, several-seeded. In waste places 

 and on ballast, N. B. and about the seaports of the Eastern and Middle States. Ad- 

 ventive from Europe. June-Sept. 



2. Lotus Americanus (Nutt.) Bisch. Prairie Bird's-foot Trefoil. (I. F. 

 f. 2085.) Annual, erect, 2.5-5 dm - ni g n - Leaves 3-foliolate, or the upper some- 

 times i-foliolate, sessile or the lower on petioles about 3 mm. long; stipules minute 

 or none; middle leaflet longer-stalked than the lateral ones, oblong, the lateral 

 lanceolate, rounded at the base, 12-17 mm - l° n g; peduncles leafy-bracted at the 

 summit, 2-2.5 cm. long in fruit; flowers about 5 mm. long, the standard darker- 

 veined; keel acute; calyx-lobes linear, about twice the length of the tube; pods 

 linear, straight, acute, glabrous, 4-7 -seeded, deflexed at maturity. In dry soil, 

 Minn, and S. Dak. to Mo., Ark., Kans., N. Mex. and Sonora. Summer. 



14. PSORALEA L. 



Herbs or shrubs, with dark glands or pellucid dots, 1-5-foliolate leaves, and 

 purple, blue, pink or white flowers, mainly in spikes or racemes ; stipules broad; 

 calyx-lobes equal or the lower longest, or the two upper ones sometimes united; 

 standard ovate or orbicular, clawed; wings oblong or falcate; keel incurved, obtuse; 

 stamens monadelphous or diadelphous; ovary i-ovuled; pod ovoid, short, inde- 

 hiscent, I -seeded. [Greek, scurfy, from the glandular dots, whence the name 

 Scurfy-pea.] About no species, of wide distribution. In addition to the follow- 

 ing, about 20 others occur in the western U. S. 



Leaves digitately 3-5-foliolate (leaflets all from the same point). 

 Plants leafy-stemmed. 



Flowers small, 4-9 mm. long. 

 Pods subglobose. 



Leaflets narrowly oblong. 1. P. lanceolata. 



Leaflets, except those of basal leaves, filiform-linear. 



2. P. micrantha. 

 Pods ovoid, or ovate. 



Pods with a short, mostly abrupt beak. 



Flowers few, scattered in slender elongated racemes. 



3. P. tenuiflora. 

 Flowers numerous clustered or crowded in racemes. 



Leaflets oblong-obovate. 4. P. obtusiloba. 



Leaflets oblong. 5. P. floribunda. 



Pods with slender sharp or elongated beak. 



Leaflets linear ; flowers in loose elongated racemes. 



6. P. linearifolia. 

 Leaflets linear-lanceolate, oblong, oblanceolate or obovate ; flowers 



spiked. 



Leaflets oblanceolate or obovate ; pubescence gray. 



7. P. collina. 

 Leaflets linear-lanceolate to obovate ; pubescence silvery. 



Leaflets linear to oblanceolate ; calyx inflated in fruit. 



8. P. digitata. 

 Leaflets oblong to obovate ; calyx not inflated in fruit. 



9. P. argophylla. 

 Flowers large, 13-17 mm. long, densely spicate. 10. P. cuspidata. 



Plants acaulescent, or nearly so, low, spreading; roots tuberous. 



Leaflets oblong-cuneate. n. P. esculenta. 



Leaflets linear-oblong. 12. P. hypogaea. 



Leaves pinnatelv 3-foliolate (the terminal leaflet stalked). 



Racemes short, on peduncles about equalling the leaves. 13. P. stipulata. 



Racemes spicate, elongated, much exceeding the leaves. 



Leaflets oblong-lanceolate, obtuse; pods 4 mm. long, nearly orbicular. 



14. P. pedunculata. 

 Leaflets ovate-lanceolate, acuminate ; pods 9-1 1 mm. long, obliquely ovoid. 



15. P. Onobrychis. 



