''Cerastium nigrescens'', commonly known as the Shetland mouse-ear, Shetland mouse-eared chickweed or Edmondston's chickweed, is an

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

found in Shetland, Scotland. It was first recorded in 1837 by botanist Thomas Edmondston, who was 12 at the time. For a long time it was synonymised with arctic mouse-ear ''

Cerastium arcticum ''Cerastium arcticum'', the Arctic mouse-ear chickweed or Arctic mouse-ear, is a flower distributed at parts of western and southern Greenland, Baffin Island, Labrador, Iceland, Scotland, Norway and Svalbard. It is a perennial herb that grows i ...

'' but it is now widely regarded as a separate species. Although reported from two other sites in the 19th century, it currently grows only on two serpentine hills on the island of

Unst Unst (; sco, Unst; nrn, Ønst) is one of the North Isles of the Shetland Islands, Scotland. It is the northernmost of the inhabited British Isles and is the third-largest island in Shetland after Mainland and Yell. It has an area of . Unst ...

(see Keen of Hamar). The numbers of ''Cerastium nigrescens'' can vary dramatically from year to year, for reasons that are unclear (probably due to a varying rates of seedling germination and survival), but the underlying trend seems stable, and there has been no change in its distribution. Mature plants may be not much more than a single shoot with one flower or can be a fist-sized cushion with as many as 40 flowers. Flowers look disproportionately large compared with the size of the plant.

References

*Scott, W. & Palmer, R. 1987. ''The Flowering Plants and Ferns of the Shetland Islands''. Shetland Times, Lerwick. *Scott, W. Harvey, P., Riddington, R. & Fisher, M. 2002. ''Rare Plants of Shetland.'' Shetland Amenity Trust, Lerwick.

External links

* * nigrescens Endemic flora of Scotland Biota of Shetland Plants described in 1837 1837 in Scotland Endemic biota of the Scottish islands {{Caryophyllaceae-stub