124 
half of July. Old fruiting catkins may be found clinging to the branches 
in August. 
30th base line district, Slave river, No. 516; Pine Lake district, Nos. 
2157, 2158, 2159, 2161, 2162; Moose (Eight) Lake district, Nos. 2156, 2160; 
base of eastern slope of Caribou mountains, Nos. 2151, 2153, 2154, 2155; 
eastern edge of Caribou Mountain plateau, No v 2152. 
S. pseudomonticola Ball. See Cont. U.S. Nat. Herb, xxii, 321 (1921), and Jour. Arn. 
Arboret. iii, 73 (1921). 
Occasional in the fringe of timber along upland lake shores. Known 
thus far in Wood Buffalo park from only two localities and from rather 
poor specimens. The species needs further study. Old fruits found during 
the first half of July. 
Pine lake, Nos. 2104, 2105; Moose (Eight) lake, No. 2106. 
S. pyrifolia Anders. S . balsamifera Barr. Balsam Willow. 
Apparently rare in Wood Buffalo park, and collected thus far only 
on the muskeg shore of an upland lake. Fruits beginning to mature June 25. 
Base of eastern slope of Caribou mountains, No. 2083. 
S. Candida Fluegge. Sage Willow. 
Common in upland muskeg thickets where it has been collected with 
immature fruits in late June, and with mature fruits during July and the first 
half of August. 
Near Heart (Raup) lake, No. 2089; Pine Lake district, Nos. 2090. 
2091, 2092; Moose (Eight) Lake district, No. 2088; Lobstick creek, Bussell , 
No. 11. 
S. Bebbiana Sarg, 3. rostrata Richards Gray Willow. 
Probably the most abundant willow in the region, commonly growing 
to a height of 15 or 20 feet, and having a stout trunk often 4 or 5 inches in 
diameter. An individual 1J inches in diameter at the base and 9 feet high 
was twenty-five years old. It is the most important constituent of the 
small tree and shrub layer in nearly all the woodlands, becoming most 
abundant in young river bottom timber and in the upland aspen woods. In 
delta plains it makes nearly pure stands over vast areas between the mea- 
dow margins and the slowly encroaching poplar timber. In the upland semi- 
open country it borders many of the prairies. Dead, semi-dry branches 
and trunks found in older woods supply a rather inferior though commonly 
used firewood. Catkins in an immature fruiting condition have been col- 
lected from June 6 to 13. During the latter part of June and early July 
the air is full of the floating seeds of this species, and by the first week 
in July the catkins have begun to fall off. 
East shore of lake Mamawi, Nos. 2107, 2108; along Quatre Fourches 
river, Nos. 540, 542; 30th base line district, Slave river, No. 539; Govern- 
ment Hay Camp district, Slave river, No. 2111; Fort Smith, Nos. 538, 
2118; Pine Lake district, Nos. 2115, 2119, 2121; Round lake, about 18 miles 
south of Pine lake, No. 2114; Peace point, Nos. 2112, 2113; Moose (Eight) 
Lake district, Nos. 2116, 2117, 2122; base of eastern slope of Caribou 
mountains, Nos. 2109, 2110. 
