''Carex bicolor'', the bicoloured sedge, is a species of

sedge The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...

native to North America, Northern Europe and Northern Asia. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natur ...

has assessed the plant's conservation status as being of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...

because it has a widespread distribution and faces no particular threats.

Description

''Carex bicolor'' is a tufted perennial sedge growing to a height of about . The grass-like leaves are mostly basal, greyish-green with blades up to long and wide, linear, strongly keeled, with parallel veins and long pointed tips. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

has a triangular stem about the same length as the leaves. It bears two or three spikes of small flowers, the terminal spike having staminate flowers for the lowest third and pistillate flowers above. The floral scale is shorter than the

perigynium In botany, a perigynium (plural: perigynia), also referred to as a utricle, typically refers to a sac that surrounds the achene of plants in the genus ''Carex'' (Cyperaceae). The perigynium is a modified prophyll, tissue of leaf origin, that enclos ...

that surrounds the

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not op ...

and has brown or reddish-black edges with a green midvein.

Distribution and habitat

''Carex bicolor'' has a pan-boreal distribution. In North America it is present in most of Canada, Greenland, in Alaska and the Aleutian Islands. In Northern Europe and Asia it is present at both low and high altitudes, but further south it is limited to higher altitudes. Its southerly limit is the mountains of Spain, France, Italy, Switzerland and Austria. It often grows in lime-rich habitats such as moist tundra, at the upper edge of beaches, near pools in wet sand, in poorly-vegetated marshes and patches of moist bare mud. It often grows in association with other sedges; in Switzerland these are often ''

Carex pallescens ''Carex pallescens'', called pale sedge, is a widespread species of flowering plant in the genus '' Carex'', native to the northeastern United States, eastern Canada, Iceland, Europe, Tunisia, and western Asia. It has unstable chromosome numbers. ...

'', ''

Carex panicea ''Carex panicea'', commonly known as carnation sedge, is a plant species in the sedge family, Cyperaceae. It is known as grass-like sedge and can be found in Northern and Western Europe, and also in north-eastern North America. The plant produc ...

'', and ''

Carex vaginata ''Carex vaginata'' is a species of sedge known by the common name sheathed sedge. Description This sedge produces stems up to 60 centimeters tall, growing from a long rhizome. The stem just below the inflorescence is sheathed in the base of ...

''. ''Carex bicolor'' was one of several species of plant not previously known in Britain, that were "discovered" growing on the island of

Rùm Rùm (), a Scottish Gaelic name often anglicised to Rum (), is one of the Small Isles of the Inner Hebrides, in the district of Lochaber, Scotland. For much of the 20th century the name became Rhum, a spelling invented by the former owner, Sir ...

in the

Inner Hebrides The Inner Hebrides (; Scottish Gaelic: ''Na h-Eileanan a-staigh'', "the inner isles") is an archipelago off the west coast of mainland Scotland, to the south east of the Outer Hebrides. Together these two island chains form the Hebrides, whic ...

in the 1940s by the botanist

John William Heslop-Harrison Prof John William Heslop Harrison, FRS FRSE (1881–1967), was Professor of Botany at King's College, Durham University (now Newcastle University). He enjoyed a brilliant career, specialising in the genetics of moths, but is now best remembere ...

, Professor of Botany at Durham University. These discoveries added to his reputation, but were later cast into doubt after investigations by classical scholar and botanist

John Raven John Earle Raven (13 December 1914 – 5 March 1980) was an English classical scholar, notable for his work on presocratic philosophy, and amateur botanist. Early life and education John Raven was born on 13 December 1914 in Cambridge, the ...

, who found that some of the plants were not present on the island at all, while others had been recently planted there; it is now considered that the claim that the plants were indigenous to Rùm was fraudulent.

References

External links

* * {{Taxonbar, from=Q2076996 bicolor Flora of Europe Flora of Northern America Plants described in 1785 Flora of Greenland