Altogether, at least 1,150 vascular plants, 275 lichens and 400 mosses and liverworts have been identified within Glacier. Waterton provides habitat for approximately 970 vascular plants as well as about 220 lichens and 200 mosses and liverworts. Forty-six rare Montana plants have been recorded in Glacier to date, of which four are found only in the park and its immediate environs.
Waterton has an unusually high number of rare plants; 30 are found only in Waterton and nowhere else in Canada.
One goal of Waterton-Glacier is to conserve biodiversity and maintain the naturally functioning ecosystem, i.e. a self-sustaining system based on the presence of interdependent relationships among a wide variety of life forms. The Crown of the Continent Ecosystem (CCE) is particularly rich in diversity for many reasons. The Continental Divide creates different weather systems and diverse forest communities and flora on each side of the mountains.
In the northern Rockies, life is arranged vertically in five tiers, called life zones. There are also zones that lie north, south, east, and west called floristic provinces.
(Zones that converge from N, S, E &W)
- Boreal Forest (northern)
- Northern Rocky Mountain
- Great Plains
- Pacific Northwest
- Arctic (remnant)
(Zones that ascend vertically)
- Aspen Parkland
- Montane Forest
- Alpine Tundra