White-tailed ptarmigan name "Tetrao (Lagopus) leucurus" by the Arctic explorer John Richardson in 1831. It was later determined that "Lagopus" had sufficient distinguishing features to be regarded as a separate genus and the bird became "Lagopus leucurus". Molecular studies have shown that "Lagopus" is monophyletic, with the rock ptarmigan ("Lagopus muta") and White-tailed ptarmigan being sister species. The position of the willow ptarmigan ("Lagopus lagopus") is less clear cut, it showing some genetic divergence over its wide range. The genus name "Lagopus" is derived from Ancient Greek "lagos" (λαγως), meaning "hare", + "pous" (πους), "foot", in reference to the bird's feathered legs.
Arctic vegetation in the spring, and flower and set seed much sooner than plants that grow in warmer conditions. Their peak metabolic rate also occurs at a much lower temperature than plants from farther south. Compact cushions of vegetation keep the plants close to the warm soil and shield the tender central growing shoot. The height of Arctic plants is also governed by snow depth. Plants that protrude above the snow are subject to strong winds, blowing snow, and being eaten by caribou, muskox, or ptarmigan. Mosses and lichens are common in the Arctic. These plants have the ability to stop growth