Draba lactea, commonly known as Milky Whitlow-grass, is a species of flowering plant in the family [[Brassicaceae]] (the mustard family). It is a small, perennial herb characteristic of Arctic and high-alpine environments, distinguished by its basal rosettes of hairy leaves and small white flowers.
Classification
- Kingdom: Plantae
- Clade: Tracheophytes
- Clade: Angiosperms
- Clade: Eudicots
- Clade: Rosids
- Order: Brassicales
- Family: Brassicaceae
- Genus: Draba
- Species: D. lactea Adams
Description
Draba lactea is a diminutive perennial herb, typically forming dense tufts or rosettes.- Leaves: The leaves are primarily basal, spatulate to obovate in shape, entire (untoothed), and covered with stellate (star-shaped) hairs, giving them a somewhat grayish appearance. They typically measure 5–15 mm in length.
- Stems: The flowering stems (scapes) are slender, leafless, and usually sparsely to densely hairy, reaching a height of 2 to 10 cm.
- Flowers: The inflorescence is a short [[raceme]] bearing 2 to 10 small, white flowers. Each flower has four petals, approximately 3–4 mm long, often slightly notched at the apex. The sepals are green and often hairy.
- Fruits: The fruits are [[silicule]]s, which are short, ovate-elliptic to oblong pods, 5–8 mm long and 2–3 mm wide. They can be glabrous (hairless) or sparsely hairy and contain several small seeds.
Habitat and Distribution
Draba lactea is a circumpolar Arctic and alpine species. It thrives in cold, exposed, and often rocky environments.- Habitat: It is typically found on well-drained, gravelly or sandy soils, rocky slopes, scree, moss heaths, and in crevices of rocks, often in areas with calcareous or base-rich substrates. It is well-adapted to the harsh conditions of the [[tundra]] and high mountains.
- Distribution: Its range includes northern North America (Alaska, Arctic Canada, Greenland), northern Europe (Svalbard, Scandinavia, Russia), and northern Asia. It is a common component of the flora in many Arctic regions.
Ecology
As an arctic-alpine plant, Draba lactea exhibits several adaptations to its cold environment, including its cushion-forming growth habit which helps to conserve heat and reduce wind exposure. Its small stature and perennial nature allow it to complete its life cycle during the short growing season.Etymology
- The genus name "Draba" is derived from the Greek word "drabē," referring to the acrid taste of some species or possibly to the sharp-tasting leaves once used as a medicinal remedy for toothache.
- The specific epithet "lactea" is Latin for "milky" or "milk-white," referring to the distinctive white color of its flowers.