RYDBERG: STUDIES ON THE Rocky Mountain Fiora 303 
PoruLus FREMoONTI Torr. 
The known range of this species was extended last summer, 
when it was collected by Professor A. O. Garrett and the writer 
in and around the town of Moab, southeastern Utah; and speci- 
mens evidently also belonging to it were seen in the Cottonwood 
and White canyons about 100 miles farther southwest. 
Willow hybrids are not uncommon in Europe and rather 
common in cultivation; but we find very rarely any references to 
any spontaneous hybrids of American species mentioned. It will 
therefore not be out of place to record the following specimens 
probably representing hybrids, although no definite proof can be 
given of their Origin. 
Salix cordata x S. monticola 
The shrubs referred here have capsules shorter than in S. 
cordata Muhl. but longer than in S. monticola Bebb; the habit 
and the bark are those of the latter: but the narrow leaves 
(although less serrate) and the bractlets are those of S. cordata 
angustata (Pursh) Anders., the form of S. cordata common in 
the Rockies. The capsules of the specimens seen usually re- 
Mained undeveloped. The staminate catkins resemble most 
those of S, monticola. S. monticola was growing mixed in with 
the supposed hybrid. S. cordata angustata is also growing in the 
Big Cotton Canyon, although no specimens of it were noticed 
in the immediate vicinity where the plants were collected. 
Utan: Big Cottonwood Canyon, below Silver Lake, July 11, 
Ae Rydberg 6877, 6878, and 688 3; July 4, 1905, Rydberg & Carlton 
15. 
The specimens resemble S. glaucops Anders. in the capsules 
and bractlets but the former are less densely hairy; the leaves 
are More like those of S. monticola, being finely serrate, glabrate 
Villous. 
Big Cottonwood Canyon. | 
a Big Cottonwood Canyon, Salt Lake City County, 
3, 1905, A. O. Garrett 1671. 
