20 CRUCIFER^E. (MUSTARD FAMILY.) 



a narrow margin. Along the Platte and westward to W. Nevada and 

 Oregon. 



4. A. lyrata, L. Low, diffuse or spreading from the base, mostly glabrous, 

 except the lyrate-pinnatifid root-leaves; cauline leaves scattered, spatulate or 

 linear with a tapering base: petals much longer than the yellowish sepals: pods 

 ascending or spreading: seeds marginless. From Colorado northward and 

 eastward. 



* * Mostly perennials: pods usual.li/ erect or ascending Jlowers mostly larger 

 and deeper-colored. 



5. A. Drummondii, Gray. Scarcely glaucous, I to 2 feet high : stem- 

 leaves lanceolate or oblong-linear and sagittate, or the lowest spatulate : petals 

 white or rose-color, fully twice the length of the sepals : pedicels and pods 

 loosely erect or ascending or spreading: -seeds wing-margined. Throughout 

 the whole Rocky Mountain region and eastAvard across the continent. Very 

 variable. 



6. A. Lyalli, Watson. Bright green or glaucous and glabrous, sometimes 

 villous below, rarely more or less canescent with stellate pubescence : stems 

 slender from a branching base, 2 to 15 inches high : radical leaves oblanceolate, 

 entire ; cauliuo oblong-lanceolate, clasping by a sagittate base : petals light 

 pink, twice longer than the sepals : style none : seeds in 2 rows, narrowly 

 winged. Proc. Am. Acad. xi. 122. A. Drummondii, var. alpina, of Fl. 

 Colorado nnd Hayd. Rep. 1871, 1872. Alpine and subalpine. Colorado, Utah, 

 Wyoming, and westward. 



7. A. canescens, Nutt. Densely and finely stellate-pubescent, 2 to 6 inches 

 high, tufted : leaves narrowly linear-oblanceolate to broadly spatulate, entire ; 

 cauline oblong and clasping : petals pale-purple : pods glabrous, tipped by a 

 thick nearly sessile stigma, more or less spreading or rejlcxed on short pedicels : 

 seeds in 1 row, broadly winged. Wyoming to Nevada and California. 



* * * Perennial: pods reflexed or recurved: style none. 



8. A. Holboellii, Hornem. More or less stellate-pubescent, rarely hirsute 

 or even glabrous : stem \ to 2 feet high, simple or branching : lower leaves 

 spatulate, entire or denticulate : petals twice longer than the sepals, white or 

 rose-color or rarely purple, becoming reflexed. A. retrofracta, Grah. From 

 the Sierra Nevada to New Mexico and Arctic America, and eastward to the 

 Saskatchewan. 



5. STBEPTANTHUS, Nutt. 



Anthers elongated, sagittate; longer filaments sometimes connate. Stigma 

 simple. Pod linear. Seeds flat, broadly winged. Ours is a perennial, with 

 stem-leaves clasping by a broad auriculate base. 



1. S. COrdatUS, Nutt. Glabrous or glaucous: stem simple, 1 to 2 feet 

 high, rather stout : leaves thick, usually repandly toothed toward the apex, 

 the teeth often setosely tipped ; lower leaves spatulate-ovate or obovate ; 

 eauline cordate to oblong or ovate-lanceolate : petals about half longer than 

 the sepals, greenish-yellow to purple : pods nearly straight, loosely spreading. 

 Mountains of Arizona, Colorado, and Wyoming, and west to the Sierra 

 Nevada. 



