LEGUMINOSAE (PEA FAMILY) 299 



Calyx and spike densely ailky-villous 3. F. compactus. 



Flowers not wnite^ 

 Leaflets SrS. 



Cflands evident 4. P. purpureus. 



' Glands wanting or obscure . . . . . . . . 5. P. pubescens. 



Leaflets 13-17 6. P. villosus. ^ 



, 1. Petalostemon c'andjdus Michx. FI. Bor. Am. 2: 49. 1803. Glabrous; 

 stems firiH and erect, sparingly branched: leaflets 7 or 9, lanceolate or linear- 

 oblong, sparingly dotted beneath: spikes oblong, in age long-cylindrical: calyx 

 glabrate:, corolla white; wing- and keel petals ovate; the standard broadly 

 cordate: ovary pubescenf.^Coming into our range from the prairie states. 



2. Petalostemon oligophyllus (Torr.) Rydb. Mem. N. Y. Bot. Gard. 

 1; ,237. .1;900. Very similar but the stems slender, ascending, freely branched: 

 leaflets 6-9, linear-oblong: spike short, ovate-oblong, becoliiing cylindric, 

 loosely flowered. — Very common; from Montana to Texas. 



3. Petalostemon compactus (Spreng.) Swezey, Nebr. Fl. PI. 6. 1891. 

 Glabrous; stem sparingly branched, 3-6 dm. high, dotted: leaflets 5-7, 

 lanceolate-oblong, obtuse, dotted beneath: spikes cylindrical, very dense and 

 much elongated; brac^ts lanceolate, as long as the flower: calyx silky- villous ; 

 the teeih lanceolate: standard cordate; the' other petals liiiear-oblong, all 

 white or nearly so. P- mqcrostachyus. — Throughout the eastern part of our 

 range. ' 



4. Petalostemon purpureus (Vent.) Rydb. 1. c. Smooth or nearly so: 

 l^afleis 5, narrowly linear: spikes globose-ovate, or oblong-bylindrical when 

 old; bracts pointed, not longer than the silky-hoary calyx: corolla rose-purple. 

 P. violaceus.- — Prairies" from the Saskatchewan to Texas, and from Colorado 

 to Indiana. 



4a. Petalostemon purpureus mollis (Rydb.) A. Nels. Stems, and leaves 

 more or less villous-pubescent: leaflets linear, usually obttisish: corolla rose- 

 polor. (P. moUis Rydb. Mem. N. Y. Bot. Gard. 1: 238.' 19000 Probably 

 P. tenuifolius Gray as to our range. — Montana to Colorado. "" '' 



5. Petalostemon pubescens A. Nels. Bot. Gaz. 31: 395. 1901. Pale with a 

 sublanate pubescence throughout i stems several-many from a large woody 

 crown, from suberect to proStrate-assurgen,t, 1-3 dm. long: leaves neither 

 glandular nor dotted, 5-foliolate; the leaflets spatulate-linear, obtuse, 10-14 

 mm. long: spike oblong, dense, silyery-lanate; bracts about as long as the ca- 

 lyx, obovate, abruptly acuminate, the piurple tip concealed by the copious' pu- 

 bescence: corolla light purple. — Southern Colorado. ' 



6. Petalostemon villosus Nutt. Gen. 2: 85. 1818. Soft-downy or silky 

 all over: leaflets 13-17, linedr or oblong, 8-10 mm. long: spikes cylindrical, 

 3-10 CBi. long, short-peduncled, sof t-villous ; bracts lanceolate, acuminate, 

 exceeding the calyx: corolla rose-purple, often pale; standard oblong; the 

 wings and keel oblong-obOvate. — Northeastern paft of our range to Wiscon- 

 sin and Missouri. ' ' 



16. HEDYSARUM L. 



Perennial herbs. ■ Leaves odd-pinnate. Calyx Srcleft, tlie lobes awl-shaped 

 and ncEtrly eiqual. Keel nearly straight, obliquely truncate, not appendaged, 

 longer than the wings. Stamens diadelphous (9 and 1). Pod flattened, com- 

 posed of several equal-sided; separable, roundish j oints connected in the middle. 



Flowers rose-color, lilac, or purple. ' • '^ ' j , ■ ■ 



'Stems and leaves cahescent' , . . ... , , . 1, H. cinerascens. 

 Stems and leaves green, glabrate or obscurely pubescent. 



Joints of loment wing-margined . . . . , . 2. H. marginatum. 



Joints of loment not wing-margined. 



Flowers tardily if at all reflexed , . . , , , 3. H. pabulare, , . 



JFlowers reflexed from the first -■. , , , . 4. H. uintahense. ' 



Flowers white or yellow. '' 



Leaflets 11-13 5. H. sulphurescens. 



, Ji^flets lS-23 6. H. philoscia. 



1. Hedysarum cinerascens Rydb. Mem. N. Y. Bot. Gard. 1: 257. 1900. 

 Cinereous-canescent: stems several, erect or decumbent, 3-G dm. high: leaflets 



