Abstract
Chromosome numbers for individuals from 87 populations of Antennaria from western Canada were counted. Naturally occurring triploid (2n = 42) hybrid populations between diploid (2n = 28) A. microphylla Rydb. and 2 tetraploid (2n = 56) species A. rosea Greene and A. umbrinella Rydb. are reported for the 1st time. With the discovery of the triploid populations, an entire euploid series (2x-8x) has been established for the genus Antennaria.