Saussurea

Saussurea is a genus of about 300 species of flowering plants in the thistle tribe within the daisy family, native to cool temperate and arctic regions of East Asia, Europe, and North America, with the highest diversity in alpine habitats in the Himalayas and East Asia. Common names include saw-wort and snow lotus, the latter used for a number of high altitude species in East Asia. They are perennial herbaceous plants, ranging in height from dwarf alpine species 5–10 cm tall, to tall thistle-like plants up to 3 m tall. The leaves are produced in a dense basal rosette, and then spirally up the flowering stem. The flowers form in a dense head of small capitula, often surrounded by dense white to purple woolly hairs; the individual florets are also white to purple. The wool is densest in the high altitude species, and aids in the thermoregulation of the flowers, minimising frost damage at night and also preventing ultraviolet light damage from the intense high-altitude sunlight.