558 Rydberg: Rocky Mountain flora 



This Is intermediate between E. elatumand E. Wheeleri. The 

 former has longer petals, the claws of which are much longer than 

 the sepals and the leaves are usually more dentate. From E. 

 Wheeleri it differs in the light yellow petals. It grows on foot- 

 hills and plains at an altitude of 1,500-3,000 m. 



Colorado: Georgetown, 1895, P. A. Rydberg (type); La 

 Plata P. O., 1898, Baker, Earle & Tracy 906 ; mesas near Pueblo, 

 1900, Rydberg & Vreeland 6igj ; Williams Canon, 1894, E. A. 

 Bcssey. 



Wyoming: Buffalo, 1900, F. Tweedy 3595- 



Erysimum radicatum sp. nov. 



Perennial with a tap-root, branched at the base ; stems 1.5 dm. 

 or less high, slightly strigose ; leaves linear-oblanceolate, sinuately 

 toothed, 4-7 cm. long, strigose ; raceme short and dense ; sepals 

 fully 1 cm. long, linear, acutish, equaling the claws of the petals ; 

 the latter light yellow, about 1 5 mm. long ; blades broadly spatu- 

 late, almost orbicular ; fruiting pedicels about 8 mm. long, ascend- 

 ing ; pods ascending, tetragonal, about 4 cm. long. 



This is somewhat related to Erysimum nivale {Cheiranthus 

 nivalis Greene) but differs in the basal rosettes of sinuate-dentate 

 leaves. It grows at an altitude of about 3,800 m. 



Colorado: Bottomless Pit (Pike's Peak), 1901, Clements 441 

 (type); also in 1900 at the same place. 



Opulaster bracteatus sp. nov. 



A shrub a meter or two high ; bark of the stems brownish- 

 gray, more or less flaky ; that of the young twigs yellowish-green, 

 glabrous or nearly so ; stipules linear-lanceolate, about 5 mm. 

 long, pubescent ; petioles 1-3 cm. long ; leaf-blades 3-7 cm. long, 

 ovate or cordate in outline, 3-5-lobed and doubly crenate, acute, 

 glabrous or nearly so on both sides, somewhat paler beneath ; 

 corymb rather many- flowered ; bracts obovate or spatulate, often 

 foliaceous and more or less persistent, pubescent ; hypanthium 

 sparingly stellate ; sepals oblong-ovate, obtuse or acutish, about 

 3 mrn. long, densely stellate on both sides ; petals white, rounded- 

 ovate, 4-5 mm. long ; carpels 2, densely stellate, united at least 

 half their length ; styles ascending. 



This resembles mostly 0. intermedins in habit and leaves, but 

 has the fruit of 0. monogynns. It differs however from both in 

 the conspicuous persistent bracts. It grows along streams in the 

 foothills of northern Colorado. 



