Draba nivalis; Snow Whitlowgrass resembles the hoary whitlowgrass (D. incana) but it lacks leaves on the flowering stems. As such it also resembles the rock whitlowgrass (D. norvegica) which has only one or two leaves on the flowering stems; the latter also has longer leaves which are also less greyish-colored. The leaves and stems are covered with short hairs. If you have a magnifying glass you can see that the hairs are star-shaped (called "stellate") or forked. This characteristic feature is also found in the Rock hoarygrass (D. norvegica). A photo blow-up of stellate hairs can be found on the page of the rock whtitlowgrass. Apparently the snow whitlowgrass grows mainly north of the major glaciers. The color of the flowers (petals) are white.
It is a member of the cabbage (= mustard) family) (Brassicaceae formerly known as Cruciferae). The Icelandic name of this species is Héluvorblóm.