117 
E. spissum Fernald. E. callitrix of most Am. auth. See Rhod. xxvii, 208 (1925). 
Apparently only occasional in cold upland muskegs. Fruiting speci- 
mens collected during the second week in July. 
Pine Lake district, No. 1991; eastern edge of Caribou Mountain pla- 
teau, No. 1990. 
E. angustifolium Roth. 
Apparently rare in Wood Buffalo park, and collected thus far only 
from a cold bog near Pine lake. In fruit July 9. 
Pine Lake district, No. 1983. 
Scirpus hudsonianus (Michx.) Fernald. Eriophorum alpinum L. Alpine COTTON- 
GRASS. 
Apparently rare in the park area, and observed thus far only in a 
muskeg near Pine lake. Specimens collected there have unfortunately been 
lost. 
S. validus Vahl. Bulrush. 
Abundant throughout the region on marshy lake shores, where it 
forms dark, bluish green bands which are very conspicuous. Found in 
flower during the latter part of June and the first half of July. Fruiting 
in August. 
Cree (Mamawi) creek, No. 1980; lower delta of Athabaska river, No. 
386; east shore of lake Mamawi, No. 1982; near Heart (Raup) lake, No. 
1977; Pine Lake district. No. 1978; Moose (Eight) lake, No. 1979; base of 
eastern slope of Caribou mountains, No. 1981. 
S. paludosus A. NqIs. 
Salt River region, Camsell, No. 92022. 
ARACEAE 
Calla palustris L. Wild Calla, or Water Arum. 
Occasional in the park area, and collected thus far only in the river 
flood-plain districts, where it flowers in late July. 
Cree (Mamawi) creek, No. 1994; Murdock Creek district, No. 1993. 
LEMNACEAE 
Lemna trisulca L. 
Apparently only occasional in the park area. It inhabits the still 
water of small slough ponds in the lowlands. 
Murdock Creek district, No. 1995. 
L. minor L, Duckweed. 
Common in the quiet water of small slough ponds and lake margins 
throughout the region. 
30th base line district, Slave river, No. 394a; Moose (Eight) lake, 
No. 1996. 
