极地雪藻（学名：）为衣藻属下的一个单细胞红色绿藻门物种，具光合作用 能力，常见于世界各地如极地或高山山脉的雪原（英语：snowfield）。这些绿藻是西瓜雪形成的其中一个原因，令雪原上呈现一片片或红或粉红的色彩。尽管早在亚里士多德时他已对由极地雪藻引起的红雪现象描述，但其实生物学家对这种生物的研究才不过一百多年。
极地雪藻跟另一个同属衣藻属的物种有着密切的关系，但两者的栖息地却有很大差异：极地雪藻只见于山上、雪原及极地，常处于极端环境，例如有限营养素、低温及强烈日照；相反作为一种中温生物的，这种植物欠缺极地雪藻为适应环境而发展出来的特殊机制，例如：使之能耐寒（英语：cryotolerant）的机制，以及能够在岩石表面、泥土里、溶雪（英语：meltwater）里及雪地上均能生长。 其次，植物的类胡萝卜素形成了一层厚厚的细胞壁, and particles on the cell wall are some characteristics that protect the 囊肿 from light, drought, and radiation stress. Although the seasonal mobile to dormant life cycle of is complex, it also helps the algae exploit its niche and survive unfavourable conditions. As a result, is one of the best known and studied snow algae. When taking account of the photoprotective（英语：photoprotective） effect of its secondary carotenoid, 虾青素, among the other adaptive mechanisms to its extreme habitat, it can be understood how became so dominant in microbial snow algae communities. Green motile offspring are produced in the spring and throughout the summer. They develop into red dormant cysts, the stage where this organism spends most of its life cycle, as the winter season begins and remain a cyst until the spring.
This alga is an interesting organism for researchers in various fields to study due to its possible role in lowering global 反照率, ability to survive in extreme environments, and production of commercially relevant compounds. Additionally, its life cycle is still being studied today in an effort to better understand this organism and amend previous classification errors.
