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R. Cyrnbalaria Pursh. Halerpesles Cymbalaria (Pursh) Greene. Sea-side Buttercup. 
Common on muddy slough and stream margins, particularly those of 
slightly saline nature, and found mainly in the lowland districts. Collected 
in flower June 23, and with both flowers and fruit July 12 and August 8. 
Government Hay Camp district, Slave river, No. 2366; Fort Smith, 
No. 733; Little Buffalo river, Russell, No. 65. 
R. Purshii Richards. Yellow Water Buttercup. 
Common in slough ponds throughout the area. Flowers collected 
during the third week in June and through most of the summer. Fruits are 
matured during July and August. 
30th base line district, Slave river, No. 734; Murdock Creek district, 
No. 2377; Government Hay Camp district, Slave river, Nos. 2378, 2379; 
Pine Lake district, Nos. 2375, 2376; base of eastern slope of Caribou moun- 
tains, No. 2374. 
R. hyperboreus Rottb. Arctic Buttercup. 
Apparently rare in Wood Buffalo park, and known thus far only from 
a single specimen collected in the Salt Plain prairies. In flower August 20. 
Near Heart (Raup) lake, No. 2368. 
R. iapponicus L. Lapland Buttercup. 
Apparently rare in the region, and found thus far only on the Caribou 
Mountain plateau, where it grows in mossy muskeg thickets. Found with 
immature fruit July 12. 
Eastern edge of Caribou Mountain plateau, No. 2359. 
R. rhomboideus Goldie. Prairie Buttercup. 
Apparently rare or occasional, and confined to the upland semi-open 
prairies. In flower and immature fruit June 17. 
Pine Lake district, No. 2373. 
R. sceleratus L. Celery-leaved, or Cursed Buttercup. 
Common on wet pond and lake shores. Found in flower from the latter 
part of June through the remainder of the summer. Mature fruits col- 
lected as early as June 26. Plants very acrid, the juice often causing a 
blistering of the skin. 
Lower delta of Athabaska river, No. 746; 30th base line district, Slave 
river, No. 745; Murdock Creek district, No. 2386; Government Hay Camp 
district, Slave river, No. 2385; near Heart (Raup) lake, No. 2384; Pine 
Lake district, Nos. 2382, 2387; Moose (Eight) Lake district, Nos. 2380, 
2381, 2383; base of eastern slope of Caribou mountains, No. 2388. 
R. aborti vus L. Small-flowered Buttbrcup. 
Oceasional, and apparently confined to upland muskegs. In flower 
June 20, and fruit July 19. Juice from leaves known to cause blistering. 
Pine Lake district, No. 2372; base of eastern slope of Caribou moun- 
tains, No. 2371. 
