136 
R. ten ell us Nutt. 
Apparently rare in the park area, and collected thus far only at a 
slough margin along Peace river just inside the western boundary. With 
flowers and fruit July 31. 
Indian graveyard, Peace river, No. 2367. 
R. pennsylvanicus L. f. Bristly Buttercup. 
* Collected thus far only in the Peace-Athabaska delta, where it is 
common. Found in fruit July 11 and during the second week in August. 
Lower delta of Athabaska river, No. 744; east shore of lake Mamawi, 
No. 2360. 
R. Macounii Britton. Macoun's Buttercup, 
Common in damp sloughs throughout the region. Flowers collected 
during the latter part of June and the first three weeks of July. Fruit 
begins to mature about mid-July and continues through most of August. 
Occasional flowers are found in early August. 
Government Hay Camp district, Slave river, Nos. 2363, 2365; Fort 
Smith, No. 741 ; Round lake, about 18 miles south of Pine lake, No. 2361 ; 
Peace point, No. 2364; sink-hole 16 miles east of Moose lake, No. 2362. 
R. acris L. Field Buttercup. 
Occasional in the region and apparently confined to the settled areas, 
where it is probably adventive. Collected in flower August 8, and with 
flowers and immature fruits August 18. The plants contain an acrid juice 
that has been known to cause blistering, vomiting, diarrhoea, and even 
death, in animals. 
Fort Smith district, No. 747, and Russell, No. 30. 
Thalictrum spars! florum Turcz. Mountain Rue. 
Rare in the region, and known only from Caribou Mountain plateau, 
where it grows in muskegs. Collected in fruit July 12. 
Eastern edge of Caribou Mountain plateau, No. 2435. 
T. venulosum Trelease. Meadow Rue, 
Common in prairie openings and open poplar woods throughout the 
upland districts, and abundant in the prairies at the base of Caribou moun- 
tains. The height of the flow r ering season is in the latter part of June and 
early July. Fruit is formed in the latter half of July and early August, 
and is falling off by August 20. 
Near Mission Farm, No. 2439; near Heart (Raup) lake, No. 2432; 
Pine Lake district, Nos. 2440, 2441; Round lake, about 18 miles south of 
Pine lake, No. 2436; Peace point, Nos. 2433, 2437; sink-hole 16 miles east 
of Moose lake, No. 2430; Moose (Eight) lake, No. 2431; base of eastern 
slope of Caribou mountains, Nos. 2434, 2442, 2443, 2444. 
