54 UNIVERSITY OF COLORADO STUDIES 
Altitude: 6,000 to 10,000 ft. Collections: Gregory Canyon; South Boulder Canyon; 
Sugarloaf Mountain. 
Salix amygdaloides Anders. PEACH WILLOW. 
This is the commonest tree willow of the county. Along streams in the plains region 
and lower foothills. 
Altitude: 4,900 to 7,000 ft. Collections: Valmont; Boulder; University campus; 
mouth of St. Vrain Canyon; “near Boulder” (Rydberg). 
Salix bebbiana Sarg. BrEBB’s WILLOW 
A bushy tree at lower stations and low shrub in high elevations. Along streams 
and margins of lakes. 
Altitude: 4,900 to 10,000 ft. Collections: Boulder; near Boulder; South Boulder 
Creek; Bear Canyon; “Boulder” (Rydberg). 
Salix brachycarpa Nutt. Dwarr WILLOW 
Altitude: 7,000 to 11,000 ft. Collection: Silver Lake. 
Salix chlorophylla Anders. WILLOW 
Altitude: 8,000 to 10,500 ft. Collection: near Fourth of July Mine. 
Salix exigua Nutt. NARROWLEAF WILLOW 
A common willow fringing streams. 
Altitude: 5,000 to 9,000 ft. Collections: Marshall; Valmont; Boulder; South 
Boulder Canyon; near junction of Fourmile and Boulder Creek. 
Salix fendleriana Anders. WILLOW 
Altitude: 6,000 to 9,000 ft. Collection: South Boulder Canyon. 
Salix glaucops Anders. WILLOW 
Altitude: 7,000 to 12,000. Collections: Eldora; Long’s Peak; ‘“‘south of Ward” 
(Rydberg). 
Salix luteosericea Rydb. S1iLKy WILLOW 
Altitude: 5,000 to 7,000 ft. Collections: South Boulder Canyon, 6,800, ft.; “near 
Boulder” (Rydberg). 
Salix nuttallii Sarg. BLAack WILLOW 
A slender tree with handsome, dark, shining leaves. Along streams and sometimes 
scattered in moist places through coniferous forests. 
Altitude: 7,000 to 10,000 ft. Collections: Sugarloaf Mountain; Bluebird Mine; 
Spencer Mountain at Eldora; “Eldora to Baltimore” (Rydberg). 
Salix perrostrata Rydb. WILLOW 
Distribution in Boulder County not known. Collections: ‘Boulder’ (Rydberg). 
Salix pseudolapponicum Seem. DWwarr WILLOW 
Altitude: 10,000 to 13,000 ft. Collections: Fourth of July Mine; “Eldora to Balti- 
more ” (Rydberg). 
Salix saximontana Rydb. Dwarr WILLow 
Altitude: 9,000 to 14,000 ft. Collections: Long’s Peak; “Arapahoe Peak” (Ryd- 
berg). 
Salix wolfii Bebb. WuiLLow 
Altitude: 8,000 to 10,500 ft. Collections: ‘Eldora to Baltimore” (Rydberg). 
