Sedges

Description

Carex arctogena is a member of the sedge family (Cyperaceae) which grows in high alpine areas. It is one of the few "bipolar" species; it has populations in Greenland, Scandinavia, Russia, Canada and southern South America.Plants in the far north and south appear to be genetically identical, having taken advantage of a similar niches on opposite ends of the globe. Carex arctogena has often been confused with the closely related Carex capitata. They were classified as one species until Harry Smith distinguished the differences between them 1940. Defining morphological characteristics of this species include: toothed scales which cover the female reproductive parts of the inflorescence, a larger seed relative to the size of the female reproductive sac (perigynia) and round perigynia which quickly taper towards the apex. It produces a single spike on each stem and has long elongated leaves which are characteristic for the genus Carex. C. arctogena has short rhizomes which grow new shoots and roots, allowing it to grow in a cespitose (tufted or turf-like) manner. This means that it can be found growing in dense tufts amongst its habitat. This species produces vegetative shoots which become leaves; these are made up from a leaf sheath covering a culm. These will grow to be 1 mm wide and have parallel veins running through the sheath. Sedges' reproductive shoots are where their inflorescences grow. Specimens are typically between 10 and 30 cm tall but tend toward the smaller sizes as the sister species, C. capitata, is usually taller. A spike will be made up from many florets. Basal florets consist of a pair of brown glumes (two sterile bracts) which subtend the perigynia. In C. arctogena the glumes are brown and significantly smaller than those of its sister species.