Quite common on gravel and sand at the outlet of Griffin Lake, B.C., and in the bed of the mountain torrent flowing into the lake at the same place. 1889. (Macoun.)
(1875.) P. coarctatum, Dougl.; Macoun, Cat., III., 408.
Not uncommon at Goldstream, Cowichan, Nanaimo and Qualicum, Vancouver Island; abundant in the Fraser valley at Yale, Lytton and on the Thompson at Spence's Bridge and Kamloops, B.C., in dry gravel and sand. 1889. (Macoun.)
(3177.) P. Douglasii, Greene. On slopes of dry hills at Sicamous, B.C., July 3rd, 1889. (Macoun.)
(3178.) P. intermedium, Nutt.
In crevices of rocks on the summit of Mount Mark, Vancouver Island, altitude 3300 feet. 1887. (Macoun.)
Spikes oblong to linear (1/2-2 in. long), dense, erect, or nearly so. Our herbarium specimens are from Brackley Point, Prince Edward Island; Norton, N.B.; Lake Nepigon, Ont.; Qu'Appelle, and Devil's Lake, Asainiboia; Kicking Horse Lake, Rocky Mountains; Indian Reservation, Kamloops, B.C.; and Cowichan River, Vancouver Island. (Macoun.)
Var. incarnatum, Watson, Gray, Man., ed. VI, 440.
P. incarnatum, Macoun, Cat., III., 409.
Spikes more slender and elongated (2-4 in. long), nodding. Our herbarium specimens are from Hull near Ottawa; Belleville, Hastings Co., Ont.; Kew Gardens, Toronto; Saskatchewan River; and Port Moody, B.C. (Macoun.)
Var. incanum, Koch.; Macoun, Cat., III., 410.
Leaves small, obtusish, more or less hoary beneath, with floccose tomentum; spikes short. Our specimens are from. Seymour, Northumberland Co., Ont.; Gull Island, Lake Nepigon; Muskeg Island, Lake Winnipeg; Medicine Hat, Assiniboia. (Macoun.)
(1880.) P. Muhlenbergii, Watson; Gray, Man., ed. VI., 441.
P. Muhlenbergii, Macoun, Cat., III., 410, in part.
Decumbent or sub-erect, scabrous with short appressed hairs. Wet places, London, Ont. (Burgess.) On the Indian Reservation, Kamloops, B.C. 1889. (Macoun.) The latter specimens are without flowers and much more hairy than those from London.
(3179.) P. emersum, Muhl.?
Differs from P. Muhlenbergii, in having the leaves much rougher with appressed hairs; lower sheaths and petioles quite smooth and the upper part of the stem and flower spike covered with glandular hairs. Under side of petiole and midrib of leaf quite hairy. Our specimens are from Short Creek and Moose Jaw and Thunder creeks; also Tail Creek and Belly River. This is the common Polygonum along all the streams throughout the prairie region.