SPIRAEA DENSIFLORA Nutt.; T. & G. Fl. N. Am. 1: 414. 1840. Under S. betulaefolia.
S. chamaedrzfolia Hook. & Arn. Bot. Beechy, 123. 1841. S. betulaefolia rosea in herb., not Gray.
This seems to be well distinct from S. lncida, which is common in the same region. The latter grows mostly in open places, while S. densiflora is found only in the deeper woods. Bridger
Mountains, Flodrnan, no. 543, and Little Belt Mountains, no. 544. The following specimens also are in the Columbia Her barium: Nuttall (type) Rocky Mountains of Columbia; Beechey's Voyage, Kotzebue's Sound ; J. M. Macoun, British Columbia, 189o.