Panarctic Flora

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3309076 Carex nigra (L.) Reichard

GBIF

Geography: Amphi-Atlantic - European - Asian.

Notes: In a Neighbor Joining analysis of AFLP data (Nakamatte and Lye 2008), both Canadian and Norwegian samples of Carex nigra nested with the Eurasian C. cespitosa. We assume that the samples studied belong to var. nigra. In the material inspected, C. nigra and C. cespitosa is rather sharply distinguished morphologically.

Carex nigra s. lat. is polymorphic, in recent Russian literature often treated as 2-3 species, sometimes with subspecies, in recent western European literature as one species with two subspecies or varieties. Egorova (1999, PAF proposal) accepted three species in the C. nigra affinity to reach the Arctic: the mainly western European C. nigra s. str., the mainly eastern European and western Siberian C. juncella (including C. wiluica), and the eastern Siberian C. appendiculata. The first-mentioned grows in open mats, the two latter have strongly tussocky growth. The differences reported - except for the tussocks - are few and quantitative. Intermediates are common, at least in northwestern Europe. Nordic authors have problems finding a morphological discontinuity. The main difference in tussock vs. mat is connected to ecology. Tussocks are mainly found in swamps or in trampled or over-grazed mires, whereas mats are typical of eroded shores and mowed sites. They behave mainly as ecological races, i.e., ecotypes. Many authors in northwestern Europe, from where both C. nigra and C. juncella were described, therefore treat them as subspecies (e.g., Hämet-Ahti et al. 1998), varieties (e.g., Hylander 1966; Elven et al. 2005), or even as forms (see comments by Chater 1980: 321). We enter var. nigra and var. juncea as ecological or eco-geographic races. The Siberian C. appendiculata may be more different and is provisionally accepted as species.

Higher Taxa