46 NORTH AMERICAN FLORA [Volume 24 



Corolla dark-blue or dark-purple, papilionaceous; petals inserted on the hypanthium, at the 

 base of the staminal tube, nearly equal in length, often with a gland near the apex, except the 

 keel-petals; blade of the banner suborbicular or round-cordate, slightly if at all retuse; blades 

 of the other petals with a rounded basal lobe, those of the keel much broader than those of the 

 wings. Stamens 9 or 10, monadelphous, united high up into a tube. Pod obliquely obovoid, 

 turgid, pubescent above, glabrous at the base, slightly exceeding the calyx-tube, but not as 

 long as the lobes, the sutures not prominent. 

 Type species Dalea Emoryi A. Gray. 



Leaves mostly pinnate; branches spreading. 



Calyx-tube glabrous; leaflets oblong-cuneate to obovate, retuse. 1. P. subnudus. 



Calyx-tube distinctly pubescent. 



Leaflets obcordate; corolla rose-purple. 2. P. polyadenitis. 



Leaflets obovate to lance-linear or oblong; corolla dark -blue. 



Calyx-lobes as long as the tube or longer. 3. P. Emoryi. 



Calyx-lobes shorter than the tube. 



Calyx-lobes subequal in length; leaves at least somewhat canes- 

 cent; branches stout. 

 Leaflets entire or merely sinuate, oval to oblong. 4. P. tinctorius. 



Leaflets distinctly dentate. 



Leaflets obovate to oblanceolate ; stem and leaves decidedly 



canescent. 5. P. dentatus. 



Leaflets linear-lanceolate; stem and leaves somewhat pubes- 

 cent but green. 6. P. arenarius. 

 Calyx-lobes unequal, the lowest one distinctly longer; stem and 



leaves glabrous; branches very slender. 7. P. junceus. 



Leaves simple; branches strongly ascending or erect. 8. P. scoparius. 



1. Psorothamnus subnudus (S. Wats.) Rydberg, sp. nov. 



Dalea polyadenia subnuda S. Wats. Bot. Calif. 2: 441. 1880. 

 Parosela polyadenia subnuda Parish, Bot. Gaz. 55: 305. 1913. 



A shrub, with spreading branches covered with orange or red glandular pustules, finely 

 canescent; leaves spreading, 1-1.5 cm. long; stipules represented by glands; rachis terete, stri- 

 gose-canescent, with a few glands; leaflets 7-11, fleshy, canescent, with a few glands, oblong- 

 cuneate to obovate, retuse, 2-3 mm. long; spikes short, terminating the branches; bracts de- 

 ciduous; calyx-tube campanulate, 2.5 mm. long, glabrous, strongly 10-ribbed, with a row of 

 conspicuous red glands in each interval; lobes subulate, ciliate, 2 mm. long; petals subequal, 

 the banner and wings with a gland near the apex; blade of the banner rounded-cordate, 3.5 mm. 

 long, the claw 2.5 mm. long; blades of the wings obliquely oblong, 4 mm. long, those of the 

 keel-petals obliquely obovate, 4 mm. long, the claws of the wings and keel-petals 2 mm. long. 



Type locality: Owens Valley, California. 

 Distribution: Known only from the type locality. 



2. Psorothamnus polyadenius (Torr.) Rydberg. 



Dalea polyadenia Torr.; S. Wats. Bot. King's Expl. 64. 1871. 

 Parosela polyadenia A. Heller, Cat. N. Am. PI. ed. 2. 6. 1900. 



A somewhat spinescent shrub, 0.5-2 m. high, with numerous divaricate conspicuously 

 glandular-pustulate branches, when young densely canescent with retrorse hairs; glands at 

 first bright-orange, in age brown; leaves divaricate, 1-2.5 cm. long; rachis densely short- 

 villous, with scattered glands; leaflets 7-13, orbicular-obcordate, 2-4 mm. long and about as 

 wide, densely short- villous and usually with a single large gland; peduncles about 1 cm. long; 

 spikes dense, 1-2 cm. long, 10-12 mm. thick; bracts lanceolate, about 3 mm. long, caducous; 

 calyx-tube 2.5 mm. long, turbinate, strongly 10-ribbed, with a row of 1-3 glands in each inter- 

 val, densely villous; lobes lance-subulate, acuminate, equaling the tube, gland-tipped; petals 

 rose-purple, usually with a single gland near the apex; blade of the banner 4 mm. long, round- 

 obovate, obtuse, the claw 3 mm. long; blades of the wings obliquely obovate, with a rounded 

 basal lobe, 4-4.5 mm. long, the claws 2 mm. long; keel-petals similar but much broader, usually 

 folded along the lower edge; pod obliquely obovate, villous and with a few large glands above, 

 glabrous below, a little exceeding the calyx-tube. 



Type locality: Border of Truckee Desert, Nevada. 

 Distribution: Western Nevada to Mojave Desert, California. 

 Illustration: S. Wats. Bot. King's Expl. pi. 9. 



