Braya longii

Braya longii
Braya longii
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Brassicales
Family: Brassicaceae
Genus: Braya
Species: B. longii
Binomial name
Braya longii
Fernald

Braya longii, common name Long's Braya or Long's northern rockcress, is a small, herbaceous, arctic-alpine flowering plant that grows only in the cool, wet and windy climate of the coastal limestone barrens of northern Newfoundland.[2] It is a narrow endemic, found in only five populations within a range of 6 km, and in one isolated population 14 km to the south,[2] all in the Strait of Belle Isle ecoregion on the extreme northwest portion of the Great Northern Peninsula of Newfoundland.[3]

Description

Long’s Braya is a small scapous (flower-stalk grows directly from the ground) perennial, with basal leaves that are fleshy and greyish-green to bluish in colour.[1] It stands erect at a height of 1-10 cm.[3] It is an obligate calciphile, meaning that it requires calcium-rich soil, and grows in limestone substrate disturbed by either natural (frost heave, wind or water erosion) or anthropogenic processes. The plant has a deep taproot for anchorage and moisture access, and dies back to the crown in winter.[3] The flowers are each connected to a central scape on stems often with a single leaf, and, like all members of the mustard family, each flower has four tall and two short stamens. White, four-petaled flowers, each with four oval, green to purple-tinged sepals arranged in a raceme,[2] have claws that are usually tinged with bluish- or reddish-violet.[1] Leaves are linear-spatulate,[2] with pointed ends, and measure 1-4 cm in length, 1-3 mm in width.[3]

Conservation status

Long’s Braya was listed as endangered under the Canadian Species at Risk Act in 1997 and the Newfoundland and Labrador Endangered Species Act in 2002.[3] Its principal threat is habitat loss due to extensive limestone quarrying, road construction and community development. Off-road vehicle use also threatens the plant's habitat, as do road and utility maintenance and climate change. Survival and reproduction are threatened by a non-native herbivorous insect, the diamondback moth, and three microbial pathogens.[3]

References

  1. 1 2 3 "Species Profile: Long's Braya". Species at Risk Public Registry. Government of Canada. Retrieved 11 June 2016.
  2. 1 2 3 4 Squires, Susan E., Luise Hermanutz and Peggy L. Dixon (April–June 2008). "Endangered, Endemic and almost Invisible – Rare Braya on the Limestone Barrens of Newfoundland, Canada" (PDF). Endangered Species UPDATE. 25 (2): 41. Retrieved 11 June 2016.
  3. 1 2 3 4 5 6 "Recovery Strategy for Long's Braya (Braya longii) and Fernald's Braya (Braya fernaldii) in Canada" (PDF). Government of Canada Publications. Government of Canada. Retrieved 11 June 2016.
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