PEA FAMILY 485 



the apex, glabrous, 5-20 mm. long; spike oblong, dense, 2-4 cm. long; bracts 

 lanceolate, shorter than the calyx, acuminate; calyx villous, 4 mm long; teeth 

 subulate; corolla rose-colored. Hills: Utah Ariz. Son. Je. 



6. P. ornatus Dougl. Stem 3-6 dm. high, glabrous, simple or slightly 

 branched; leaflets 5-7, oolong to obovate, obtuse or retuse at the apex, 5-15 mm. 

 long, glabrous; spike short and dense, 2-4 cm. long, about 1.5 cm. thick; bracts 

 and calyx silky-pilose, with long brownish hairs; calyx-teeth triangular, subulate; 

 corolla rose-colored. Mountain slopes: Ore. Ida. Nev. Son. Submont 

 My-Jl. 



7. P. purpureus (Vent.) Rydb. Stems several, erect or ascending, 3-10 

 dm. high; leaflets 3-5, narrowly linear, 8-20 mm. long, strongly involute; spikes 

 oblong or cylindric, 1-5 cm. long; bracts oblanceolate, abruptly acuminate; 

 calyx densely silky-velutinous, 3 mm. long; teeth triangular; corolla violet or 

 purple, rarely white. P. violaceus Michx. Prairies, plains or hills: Ind. Ark. 

 N.M. Sask. Plain Submont. Je-Jl. 



8. P. mollis Rydb. Stems several, erect, densely villous, 3-4 dm. high; 

 leaflets 5, densely short-villous, linear, 10-15 mm. long, 1.5-2 mm. wide, obtuse; 

 spike cylindric or oblong, 2-4 cm. long; calyx densely silky-villous, yellowish or 

 ferruginous; teeth lanceolate; corolla rose-purple. Dry plains and hills: Mont. 

 Colo. Je-Au. 



9. P. pubescens A. Nels. Stem 1-2 dm. high, sublanate; leaflets 5, nearly 

 glabrous above, sublanate beneath, 10-14 mm. long; spike oblong, 2-5 cm long, 

 less than 1 cm thick; calyx 4-5 mm long; lobes shorter than the tube; corolla 

 light purple. Plains: Colo Plain. 



10. P. villosus Nutt. Perennial, with a taproot; stems several, ascending 

 or decumbent, 3-6 dm. high, densely villous; leaflets 7-17, approximate, linear 

 to oblong, silky-villous, 6-12 mm. long; spikes cylindric, 2.5-8 cm. long; calyx 

 densely villous; teeth subulate; corolla rose-purple, pink, or rarely white. Sand 

 hills: Minn. Mo. Tex. Colo. Sask. Plain. Jl-S. 



16. ROBINIA L. LOCUST-TREE. 



Shrubs or trees, often with spine-like stipules. Leaves alternate, odd-pin- 

 nate, with entire leaflets. Flowers in axillary or terminal racemes. Calyx cam- 

 panulate, 5-lobed, the two upper lobes more united than the rest. Corolla white, 

 pink, or purplish; banner with a broad reflexed blade; wings curved, free; keel- 

 petals incurved, united at the base. Stamens 10, diadelphous, or the upper fila- 

 ment united with the tube up to the middle. Pods narrow, flat, short-stalked, 

 many-seeded; seeds oblique, with a crustaceous coat. 



Inflorescence, leaves and fruit glabrous. 1. R. Pseudacacia. 



Inflorescence and fruit hispid; leaves finely puberulent. 2. R. neomexicana. 



1. R. Pseudacacia L. Tree 6-35 m. high, with firm brown bark, and 

 spreading branches; stipular spines 3-10 mm. long; leaflets 9-19, thin, 2.5-4.5 

 cm. long, elliptic or oval, glabrous; calyx finely silky-strigose; teeth triangular, 

 2 mm. long; corolla 15-20 mm. long, white, except a yellow spot on the banner; 

 pods 5-10 cm. long, 10-15 mm. wide. (?) R. coloradensis Dode. Woods: Pa. 

 la. Okla.; cult, and nat. as far as Ont. Ida. Utah. My-Jl. 



2. R. neomexicana A. Gray. Tree 6-8 m. high, with ascending branches; 

 stipular spines 5-20 mm. long, often curved; leaflets 9-19, elliptic, oval, or ovate, 

 2-3 cm. long, strigose-puberulent; calyx glandular-hirsute and strigillose; teeth 

 lanceolate, or the upper two ovate, 3 mm. long; corolla about 2 cm. long, pale 

 rose-colored; pod 5-8 cm. long, nearly 1 cm. wide. Along streams: Colo. 

 N.M. Ariz. Nev. Submont. My-Je. 



17. PETERIA A. Gray. 



Perennial herbs or undershrubs. Leaves alternate, odd-pinnate, with entire 

 leaflets and the stipules transformed into diverging spines. Flowers drooping, 

 in virgate racemes terminating the branches. Calyx tubular, gibbous on the 

 upper side; teeth triangular-subulate or lanceolate, the upper two more or less 



