Part 1, 1919] FABACEAE: PSORALEAE 



L3 



Pod sparingly strigose. 



Leaflets from linear to broadly oblanceolate \. p. lanceolatum. 



Leaflets narrowly lmear. 2 . P. micranthum. 



Pod densely long-villous; leaflets oblanceolate to obovate. X. p Purshii 



Racemes lax and elongate, 3-7 cm. long; calyx-lobes acute 



Leaflets oblanceolate; pod densely villous. <". p. stenoslachys. 



Leaflets narrowly linear; pod merely strigose. 5 P stenohlivllum 



Pod ovate, more gradually tapering into the beak; corolla mostly blue, rarelv 

 purplish. 

 Stem-leaves developed normally. 3-5-foliolate. 



Flowers distinctly pedicelled; blades of the wings mostly obliquely 

 obovate. II. Tenuiflora. 

 Calyx-lobes acute. 



Leaflets narrowly linear; corolla 7-8 mm. long; pod gradually 



T b fl al : ed K a ,. , ^ P - Unearifolium. 



.Leaflets broader; corolla 5-6 mm. long; pod abruptly short- 

 beaked. 

 Stem-leaves with oblanceolate, oblong, or linear leaflets. 



Racemes short, few-flowered; flowers about 5 mm. long / 



mostly 1 or 2 at each node; leaves rarely 5-foliolate. ' Y P. lenuiflorum 

 Racemes elongate, many -flowered; flowers about 6 mm. 

 long, usually 2-4 at each node; stem-leaves often 5- 



<;„J? 10late - ■«,».. u ,, ., Y P. floribundum. 



Stem-leaves with obovate or broadly oblanceolate leaflets- 



flowers 6 mm. long, usually 2-4 at each node. ' -9. P. Bigelovii. 



l_alyx-lobes rounded or obtuse at the apex; corolla about 4 mm. 



Flowers sessile or nearly so; blades of the wings obliquely oblanceolate 



III. DlGITATA. 



Calyx accrescent in fruit; leaflets linear or linear-oblanceolate. Y\. P digitatum 



Calyx not accrescent m fruit; leaflets oblanceolate to obovate 



Plant green; lowest calyx-lobe not much longer than the rest. 12. P collinum - 

 Plant silvery-white; lowest calyx-lobe much exceeding the rest 



about equaling the corolla. ^3 p areoihvllum 



Stem-leaves reduced to small subulate scales; blades of the wings obliquely 



oblanceolate. IV. Juncea. h 14. P. junceum. 



1. Psoralidium lanceolatum (Pursh) Rydberg. 



Psoralea lanccolala Pursh. Fl. Am. Sept. 475. 1814 



Psoralea elliptica Pursh. Fl. Am. Sept. 741. 1814. 



Psoralea arenaria Nutt. Gen. 2: 103. 1818. 



Psoralea laxiflora Nutt. ; T. & G. Fl. N. Am. 1: 299 1838 



? Psoralea scabra Nutt.; T. & G. Fl. N. Am. 1: 300. 1838 



Lotodes ellipticum Kuntze, Rev. Gen. 193. 1891. 



Lotodes ellipticum angustissimum Kuntze, Rev. Gen. 193. 1891. 



A perennial, with a creeping branched rootstock; stem 1.5-4 dm. high, aromatic, glandular- 

 punctate throughout, sparingly strigose; leaves palmately 3-foliolate; stipules linear-lanceolate 

 to subulate, 3-10 mm. long; petioles 1-2 cm. long; leaflets 1-4 cm. long, oblanceolate to linear 

 or those of the earlier leaves obovate-oblanceolate, acute to rounded and mucronate at the apex, 

 sparingly strigose, especially along the veins beneath, and conspicuously punctate; peduncles 

 2-5 cm. long; racemes short, 1-2.5 cm. long; bracts minute; calyx campanulate, sparingly 

 strigose, 2 mm. long; lobes nearly equal, obtuse, glandular-punctate; corolla white or slightly 

 purple-tinged, 5-6 mm. long; banner almost orbicular; blades of the wings obliquely oblong- 

 oblanceolate; keel-petals scarcely lobed at the base and usually purple-tipped; stigma capitate; 

 pod globose, 5 mm. long, conspicuously glandular-warty, sparingly strigose or glabrate, the 

 beak short, erect. 



Type locality: Banks of the Missouri [probably Montana] 



Distribution: Missouri to Saskatchewan, Alberta, and Arizona 



Illustrations: Hook. Fl. Bor. Am. pi. 51; Britt. & Brown, 111. Fl. /. 2086; ed. 2. /. 2491. 



2. Psoralidium micranthum (A. Gray) Rydberg. 



Psoralea micranlha A. Gray, in Torr. Pacif. R. R. Rep. 4- 77 1857 

 Lotodes micranthum Kuntze, Rev. Gen. 194. 1891. 



A perennial, with a creeping branched rootstock; stem glabrous or sparingly strigose, glan- 

 dular-punctate; leaves digitately 3-foliolate; stipules subulate, early deciduous; petioles' 1.5-3 

 cm. long; leaflets narrowly linear, 1-5 cm. long, 1-3 mm. wide, sparingly strigose or glabrous, 

 acute at both ends; peduncles 2-4 cm. long; racemes more lax than in the preceding, 2-5 cm. long'; 



