100 
POTAMOGETONACEAE 
Potamogeton gramineus L,, var. graminifolius Fries. P. heterophyllus of most recent 
Am. auth., not Schreb. See Rhod. xxiii, 189 (1921). Pondweed. 
Common in shallow lakes and slough ponds, and abundant in the lower 
deltas of Athabaska and Peace rivers. Collected in fruit during late July 
and the first three weeks of August. 
East shore of lake Mamawi, No. 1548; Murdock Creek district, No. 
1546; Fort Smith, No. 135; Moose (Eight) Lake district, No. 1545; Indian 
graveyard, Peace river, No. 1547. 
P. praelongus Wulf. 
Common in the deeper water off-shore in relatively shallow lakes. 
Fruiting in mid-August. 
Murdock Creek district, No. 1572; Moose (Eight) lake, Nos. 1571, 
1570. 
P. Richardsonii (A. Bennett) Rydb. 
Abundant in shallow lakes and slough ponds throughout Wood Buffalo 
park. In lake Mamawi it is associated with P. vaginatus in the great 
patches of weed that clog the broad expanse of shallow w T ater. Flower buds 
collected June 16, flowers June 26, and mature fruits from late July to the 
third week in August. 
Lake Mamawi, No. 1551; 30th base line district, Slave river, No. 
134; Murdock Creek district, No. 1556; Pine Lake district, Nos. 1557, 
1559; Moose (Eight) Lake district, Nos. 1553, 1554, 1555, 1560; sink- 
hole 16 miles east of Moose lake, No. 1552; Indian graveyard, Peace river, 
No. 1558. 
P. zosteriformis Fomald. See Mem. Gray Herb, iii, 36-40 (1932). 
Apparently common in shallow, marshy lakes and slough ponds. 
Fruiting specimens collected in late July and early August. 
Murdock Creek district, No. 1565; Moose (Eight) lake, Nos. 1566, 
1567. 
P. Friesii Rupr. 
Apparently common in shallow lakes and slough ponds. Fruiting 
in late July. 
Murdock Cree district, No. 1564; Moose (Eight) lake, No. 1563. 
P. pusslfes L., var, polyphyllus Morong. 
Collected, thus far, only in an abandoned stream channel in the Atha- 
baska delta. In fruit in mid-August. 
Cree (Mamawi) creek, No. 1569. 
P. panormiianus Biv. 
Probably common on the shallow marshy shores of lakes. 
Moose (Eight) lake, No. 1568. 
