125 
S. pedicellaris Pursh, var. tenuescens Fernald. See Rhod. xi, 162 (1909). 
Apparently rare or only occasional in the park area, and collected thus 
far only in an upland muskeg thicket. In fruit July 9. 
Pine Lake district, No. 2103. 
S. athabascensis Raup. See Rhod, xxxii, 111 (1930). 
Collected thus far only from its type locality, a muskeg thicket about 
1 mile north of the Moose (Eight) Lake ranger station. In fruit August 17. 
Moose (Eight) Lake district, No. 8129. 
S. petiolaris Smith. 
Common at slough margins and occasional at the edges of upland 
semi-open prairies. In fruit in mid- June. 
East shore of lake Mamawi, Nos. 2123, 2124; 30th base line district, 
Slave river, Nos. 567, 569; Fort Smith, No. 568; Pine Lake district, No. 
2125. 
S. planifolia Pursh. S. ehlorophylla Anders. See Jour. Am. Arboret 1, 75 (1919). 
Abundant at slough and prairie margins, and on local river flood-plains 
throughout the region. It is the pioneer, colonizing willow at the margin 
of nearly every wet meadow, and small bushes of it are Usually found well 
out from the main mass of shrubbery that lines such places. Fruiting season 
apparently at its height from the middle to the last of June, but old fruiting 
catkins are often found clinging to the branches in August. 
East shore of lake Mamawi, Nos. 2144, 2145, 2146; along Quatre 
Fourches river, No. 515; 30th base line district, Slave river. No. 513; 
Murdock Creek district, No. 2148; Pine Lake district, Nos. 2149, 2150; 
Moose (Eight) lake, No. 2147; base of eastern slope of Caribou mountains, 
No. 2142; eastern edge of Caribou Mountain plateau, No. 2143. 
S. Nelsonii Ball. 
This species may prove, upon further study, to be only a variety or 
form of S. planifolia Pursh. Schneider, in monographing North American 
willows, expressed this opinion very clearly (62% Occasional at slough 
margins. In fruit during the latter half of June. 
Fort Smith, No. 514; Round lake, about 18 miles south of Pine lake, 
No. 2141. 
S. arbusculoides Anders. 
A common willow of muskeg and slough margins throughout the region. 
It also appears in the fringe of the timber that grows on local river flood- 
plain deposits. Although often a low T bush, it sometimes grows to a height 
of 10 feet. Fruiting catkins collected from June 12 to the first week in July. 
A few old catkins often cling to the branches, and have been so collected 
in mid -August. 
30th base line district, Slave river, No. 550; Government Hay Camp 
district, Slave river, No. 2097; Fort Smith, No. 2096; Pine Lake district, 
Nos. 2099, 2100; Peace point, No. 2098; Moose (Eight) Lake district, Nos. 
2095, 2101; base of eastern slope of Caribou mountains, No. 2094; eastern 
edge of Caribou Mountain plateau, No. 2093. 
91963—5 
