POLYGONUM ENGELMANNII Greene, Bull. Cal. Acad. 1: 126. 1884.
This has hitherto only been collected in the higher mountains of Colorado. It is not uncommon in central Montana at an alti tude of 6000 feet or more. Cottonwood Creek, July 3o, 1896, Flodman, no. 400. Sweet Grass Caiion, Crazy Mountains, Sep tember 8th, no. 399.