Alpine antennaria is a small alpine herb with green-gray coloring and only female flowers that occurs sporadically throughout the mountainous regions of Denali. This species grows in alpine tundra and meadows, usually in swales and other moist sites. Growing from a creeping, freely branched underground stem, the plants are mat-forming. Several flowering stalks are produced above a tight basal rosette of leaves. The leaves are oblanceolate, 0.5-2.5 cm long, abruptly sharp-pointed, green to gray, hairless to slightly hairy above and gray tomentose below. The middle and top stem leaves have linear, dark brown scarious tips. Stems are short, 3-15 cm tall, leafy, densely gray-haired and bearing 2-5 heads in a rounded cluster. The inflorescences are surrounded by many narrow bracts, the tip dark and scarious, similar to the stem leaf tips. Fused purple petals are 3-5 mm long, overshadowed by the white, hair-like pappus (modified sepals), 4-6 mm long. All plants of this clonally reproducing species are unisexual and produce only female flowers. Fruits are achenes, with a tuft of white hairs (pappus). Overall, the flowers have a soft, white appearance due to the pappus, leading to the common name of 'alpine catsfoot' or 'alpine pussytoes.' This species can be distinguished from multi-headed Antennaria friesiana because it lacks glandular hairs on leaves and stems.
This species flowers in mid-summer, the stem expanding as the flowers set fruit in the fall (Aiken et al. 2003). Antennaria alpina is perennial.
A. alpina is gynoecious: plants only produce flowers of one sex, and female plants make up the vast majority of the population. As such, the flowers can set seed without fertilization (apomixis), and the species is clonally reproduced. Seeds are dry capsules, with the persistent pappus serving to catch the wind. Male plants are occasionally found, so there is a possibility of sexual reproduction, and gene flow from hybridization with other species.
Antennaria alpina is a circumpolar species with an arctic-alpine distribution. In North America, this species occurs southwards from Alaska along the Rocky Mountains into the Yukon, B.C., and Montana, and eastwards to Northwest Territory, Nunavut, and northeastern Canada including Ontario, Quebec and the Maritime provinces then further east to Greenland and Europe. This species distribution in Alaska is primarily located in the mountains of southern Alaska westward to Unalaska, with isolated localities in the Seward Peninsula, Brooks Range and the North Slope. In Denali, A. alpina occurs in alpine areas on both sides of the Alaska Range crest, including the Kantishna Hills.
This species is found primarily on south-facing slopes, at moderately high elevations. It's moderately common at 900-1100 m, but overall not an abundant species. Its frequency is positively correlated with slope. Specimens on northern aspects occur on a larger range of slopes.