97 
E. preallum Raf. E. rohustum A.Rr. E . hyemale L., var. robuslum (AJBr.) A. A. Eat. 
Scouring Rush. 
Common on the higher parts of sand-bars along the main rivers, and 
in open sandy plaees on the uplands. Observed in fruit along upper Slave 
river June 14, but collected elsewhere only in sterile condition. Known 
to be poisonous to cattle and horses, especially when eaten in its mature 
stages. 
Along Peace river near the Slave, No. 74; 30th base line district, Slave 
river, No. 73; Peace point, No. 1500; sink-hole slough 16 miles east of 
Moose lake, No. 1499. 
E. variegatum Schleich. Northern Scouring Rush. 
Apparently rare in Wood Buffalo park, and confined to sandy lake 
shores. Fruiting stems collected July 6. 
Pine lake, No. 1463. 
E. scirpoides Michx, 
Abundant in timbered muskegs throughout the area. In many places 
it makes a large part of the ground cover beneath the black spruces. Found 
in fruit between June 20 and August 6. 
Pine Lake district, Nos. 1467, 1468; Moose (Eight) Lake district, No. 
1469; base of eastern slope of Caribou mountains, Nos. 1465, 1466. 
LYCOPODIACBAE 
Lycopodium annotinum L. See Rhod. xvii, 123 (1915). Stiff Club-moss. 
Occasional in rich spruce woods where it grows in a deep mat of mosses. 
Fruiting cones just beginning to form on July 1 in Pine Lake district, and 
maturing on the slopes of Caribou mountains July 12. 
Pine Lake district, No. 1501; eastern slope of Caribou mountains, No. 
1502. 
L. compl an a turn L. Ground Cedar. 
Common in dry, usually jackpine, woods on the uplands. In the older 
pine forests it sometimes forms dense mats which exclude nearly all other 
plants. Fruiting cones just beginning to form in the latter half of June, 
about f inch long July 5, and maturing in late July. 
Pine Lake district, Nos. 1504, 1505; Salt mountain, No. 1507; near 
sink-hole 16 miles east of Moose lake, No. 1506; eastern edge of Caribou 
Mountain plateau, No. 1503. 
PINACEAE 
Picea glauca Voss. P. canademis BSP., not Link, P. alba Link. See Rhod. xvii, 
59-62 (1915). Canada, or White Spruce. 
The predominating forest tree throughout Wood Buffalo park. It 
reaches its best development on the banks of the main rivers and upon 
the better-drained soils of the uplands. Seventy-five foot trees, 2 feet in 
diameter at the base, are common in the lowlands, and larger ones, 3 feet 
or more in diameter, occur in localized areas in the country between Pine 
Lake district and Caribou mountains. A 75-foot tree measured at the 
Government Hay Camp was 110 years old. The uses of the Canada spruce 
