PEA FAMILY 501 



!• R. scaphoides (M. E. Jones) Rydb. Stem coarse^ strigose, 5-7 dm. 

 high; leaflets about 11, eUiptic, 1-2.5 cm. long, grayish-strigose beneath, glabrous 

 above; calyx black-hairy, 8 mm. long; teeth 2 mm. long, triangular-subulate; 

 corolla white; pod coriaceous, glabrous, reticulate; stipe about 1 cm. long; body 

 oblong, acute, about 15 mm. long. Astragalus arredus scaphoides M. E. Jones. 

 Sage-brush plains: Mont. Plain — Suhmont. Je. 



2. R. arcta (Sheld.) Rydb. Perennial, with woody base, much branched, 

 1.5-5 dm. high, striate, glabrous; leaflets 13-21, rather distant, oblanceolate, 4- 

 10 mm. long, glabrous, or nearly so; calyx about 10 mm. long; teeth subulate; 

 corolla purplish, about 18 mm. long; pod oblong-elhpsoid, 2-2.5 cm. long, taper- 

 ing at both ends; stipe 5-8 mm. long, somewhat sulcate on the ventral side, 

 A. Preussii latus Jones. A. Preussii arctus Sheld. Sandy soil: Utah. Son, 

 My-Je. 



3. R. Preussii (A. Gray) Rydb. Stems glabrous, 3-4 dm. high; leaflets 

 13-17, fleshy, obovate or rounded, usually retuse, 1-2 cm. long, glabrous; calyx 

 minutely strigose or glabrate; tube 7-8 mm. long; teeth subulate, 1.5 mm. long; 

 corolla purple, 20-25 mm. long; stipe of the pod 4 mm. long; body oblong, acute 

 at both ends, 2.5 cm. long. A. Preussii A. Gray. River banks: Utah — Ariz, 

 — s Calif.— Nev. Son, Mr-My. 



4. R, praelonga (Sheld.) Fedde & Sydow. Stems 4-10 dm. high, glabrous 

 or nearly so; leaflets 15-21, oval, 1-3.5 cm. long, glabrous or nearly so, often 

 retuse; raceme densely flowered; calyx sparing!}^ gtrigillose; tube 6 mm. loiig; 

 teeth subulate, 2-3 mm. long; corolla ochroleucous, 16-18 mm. long; pod ovoid, 

 abruptly acute, 2-3 cm. long, 10^-12 mm. thick, glabrous, indistinctly reticulate. 

 A. praelongus Sheld. A. sabulosus M. E. Jones. Dry ground: Colo. — N.M. — 

 Calif. Son. — Submont. Ap-My, 



5. R. Pattersonii (A. Gray) Fedde & Sydow. Stems 3-6 dm. high, more or 

 less strigose; leaflets 11-21, oblong, thick, acute or obtuse, 1-2 cm. long, glabrous 

 above, strigose beneath; flowers usually nodding; calyx strigose; tube about 8 

 mm. long; teeth subulate, 3-4 mm. long; corolla ochroleucous, 18-20 mm. long; 

 pod ovoid, long-acuminate, 2-2.5 cm. long, 7-8 mm. thick, glabrous, reticulate. 

 A. Pattersonii A. Gray. Foot-hills and plains: Colo. — Utah. Son. — Suhmont. 

 My. 



28. CTENOPHYLLUM Rydb. 



Stout perennials, with often several stems rising from the same root and more 

 or less stoloniferous. Leaves pinnate, with 11-19 leaflets, which usually are 

 indistinctly jointed to the rachis; stipules ovate, free from the petioles, but 

 (especially the lower) united back of the stem. Peduncles usually equalling the 

 leaves; raceme short. Calyx cylindro-campanulate, very gibbous at the base on 

 the upper side. Corolla ochroleucous, with narrow petals; keel almost straight. 

 Pod oblong, terete, coriaceous, with a subfleshy epicarp, in age cross-wrinkled, 

 with thick and prominent sutures, neither of which is inflexed. 



Leaflets narrow. 



Leaflets filiform or nearly so, 2-4 cm. long. 1-2 mm. wide. 1. C pectinatum. 



Leaflets Unear. 2-3 cm. long. 3-4 mm. wide. 2. C. Grayi. 



Leaflets oblong to broadly obovate. 3. C adanum. 



1. C. pectinatum (Hook) Rydb. Stems 3-5 dm. high, erect or decumbent 

 at the base; leaflets 15-21, minutely strigose when young, soon glabrate; raceme 

 short and dense, 5-20-flowered; calyx sparingly black-strigose; tube 5-7 mm. 

 long; teeth subulate, 2 mm. long; corolla ochroleucous, about 2 cm. long; pod 

 oblong-ellipsoid, 1.5-2 cm. long, terete, 8 mm. in diameter. Astragalus pectin- 

 atus Dougl. Dry plains: Man. — Kans.— Colo. — Alta. Plain — Suhmont My- 

 Je. 



2. C. Grayi (Parry) Rydb, Stems 3-i dm. high, strigose; leaflets 7-13, 

 obtuse, glabrous above, sparingly strigillose beneath; raceme short and dense; 

 calyx strigillose, with blackish hairs; tube 7 mm. long; teeth subulate, 2-3 mm. 

 long; corolla ochroleucous, 2-2.5 cm. long; legume oblong-ovoid, glabrous. A. 

 Grayi Parry. Dry draws and hills: Wyo. Plain, Je, 



