101 
P. foliosus Raf. var. Maeellus Femaid, See Mem. Gray Herb, iii, 46-51 (1932). 
Common in shallow lakes and ponds. Collected in fruit during the 
third week in August. 
30th base line district, Slave river, No. 132; sink-hole 16 miles east of 
Moose lake, No. 1561; Moose (Eight) lake, No. 1562. 
P, vaginatus Turcz. See Rhod. xviii, 131 (1916), and xx, 191 (1918). 
Common in shallow marshy lakes, and abundant in the open shallow 
water of lake Mamawi, where, with P. Rickardsonii, it forms most of the 
large patches of weed. Flowers collected June 26 and fruits in mid-August. 
Lake Mamawi, No. 1549; Pine Lake district, No. 1550. 
P. filiformis Pers var borealis (Raf.) St. John. See Rhod. xviii, 134 (1916). 
Common on sandy bottoms of shallow lake margins. Immature fruits 
collected July 3, and mature ones August 14. 
Pine lake, Nos. 1573, 1575; Moose (Eight) lake, No. 1574. 
P, filiformis Pers., var. Macounii Morong. See Rhod. xviii, 136 (1916). 
Probably common in shallow lakes and slow streams. Found growing 
in the noticeably brackish water of Salt river. Immature fruits collected 
June 26. 
Near Heart (Raup) lake, No. 1577; Pine Lake district, No. 1576. 
P. pectinatus L. 
Probably common in shallow lakes that have sand or gravel bottoms. 
Fruiting specimens collected in mid- August. 
Moose (Eight) lake, No. 1578. 
NAJADACEAE 
Najas flexilis (Willd.) Rostk. and Schmidt. Naiad. 
Occasional on shallow sandy margins of lakes. Collected in fruit 
August 14. 
Moose (Eight) lake, No. 1579. 
SCHEUCHZERIACEAE 
Triglochin maritimum L. Arrow Grass. 
Common in semi-alkaline muskegs, sloughs, and wet prairies, and 
abundant in saline flats on the Salt Plains. Flowers found between mid- 
June and mid-July, and mature fruits during the first half of August. 
Government Hay Camp district, Slave river, No. 1586; near Heart 
(Raup) lake, No. 1585; near Mission Farm, No. 1582; Pine Lake district, 
No. 1584; Moose (Eight) Lake district, No. 1583; junction of Nyarling and 
Little Buffalo rivers, Russell , No. 10. 
T. palustre L. Marsh Arrow Grass. 
Occasional in wet meadows on the upland. Observed in flower July 14, 
immature fruit July 25, and mature fruit during the third week in August. 
Along the trail between the Heart Lake district and Fitzgerald, No. 
1580; near Round lake, about 18 miles south of Pine lake, No. 1581. 
