(yellow arctic draba)
Select an option below for more information on this species
Photo of Draba nivalis by Carl Roland
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Draba nivalis is a tiny, tufted perennial forb in the mustard family (Brassicaceae) with a
basal rosette of leaves and leafless flowering stems. This is an alpine species of scree slopes, rock outcrops, and dry, gravelly tundra on both sides of the Alaska Range crest in Denali. Leaves are
oblong-
obovate in shape,
entire margined, and covered with a dense gray pubescent of
stellate (star-like) hairs. Flowers (3-12) are arranged in a
raceme that elongates in age. Like all mustards,
D. nivalis has 4 petals, 4
sepals and 6
stamens. Petals are white. The fruit is a
glabrous, flattened,
linear-
elliptic silique, 6-9 mm long, longer than the
pedicel.
Draba longipes is another common, white-flowered
Draba, but it has larger
oblanceolate leaves, and the
pedicels are longer than the
siliques. There are many other uncommon species of
Draba in the park that can look similar, people wishing to make a certain identification for any
Draba species should consult a technical flora.
Draba nivalis typically flowers early to mid-summer depending on micro-site conditions.
D. nivalis is
monoecious with bisexual flowers. Flowers are self-fertilizing, with some outcrossing due to insect visits (
Mulligan and Findlay 1970). Fruits are
dehiscent and forcibly eject seeds. Seeds have no specialized dispersal adaptations.
Draba nivalis is a circumpolar species with an arctic-alpine distribution, ranging from Eurasia through Alaska, east to Labrador and Greenland and south through British Columbia and Alberta. In Alaska this species occurs scattered in the mountains statewide except is apparently absent from the southeast panhandle and the Aleutian chain. In Denali D. nivalis occurs in the mountains on both sides of the Alaska Range.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
D. nivalis is found in the park growing at elevations from 663 m to 1787 m with an average site elevation of 1244 m. It is more commonly seen on south-facing slopes. While it is observed in the park at a wide range of slope angles, (flat to 39 degrees) it prefers steeply angled sites with an average slope of 24 degrees.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
D. nivalis is an alpine species that grows in gravelly or rocky soils such as fell-fields, scree, tundra, terraces, and cliffs. Soil pH at sites where it was found ranged from 4.2 to 6.9 with an average pH of 5.4.
Dry sites in the mountains.
