558 RYDBERG: Rocky MOUNTAIN FLORA 
This is intermediate between £. e/atum and E. Wheelert. The 
former has longer petals, the claws of which are much longer than 
the sepals and the leaves are usually more dentate. From Z. 
Wheeleri it differs in the light yellow petals. It grows on foot- 
hills and plains at an altitude of 1,500—3,000 m. 
CoLorapo: Georgetown, 1895, P. A. Rydberg (type); La 
Plata P. O., 1898, Baker, Earle & Tracy 906 ; mesas near Pueblo, 
1900, Rydberg & Vreeland 6193; Williams Cafion, 1894, £. A. 
Bessey. 
WyominG: Buffalo, 1900, 7. Tweedy 3595. 
vErysimum 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 15 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. 
CoLorapo : Bottomless Pit (Pike’s Peak), 1901, Clements 447 
(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 mm. 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 O. intermedius in habit and leaves, but 
has the fruit of O. monogynus. It differs however from both in 
the conspicuous persistent bracts. It grows along streams in the 
foothills of northern Colorado. 
