3309011 Carex saxatilis L.
- L., Sp. Pl.: 976 (1753). Lectotype (LINN): Europe. Herb. Linn. 1100.51 (Marshall 1907: 366).
Notes: Egorova and Elven: Opinions about Carex saxatilis differ. Hultén and Fries (1986) included C. saxatilis subsp. saxatilis as narrowly amphi-Atlantic in northeastern Ellesmere Island, Greenland, Svalbard, Iceland, the Faeroes, the British Isles, Fennoscandia, and northwestern European Russia; and C. saxatilis subsp. laxa from northeastern European Russia throughout northern Asia and North America, but not in Greenland or northeasternmost Canada.
Another model was proposed by Ford et al. (1991) investigating allozyme variation, by Ford and Ball (1992) investigating morphological variation by 'classical' numerical taxonomy in a wide sample including material from northwestern Europe, European Russia, Siberia, North Ameria, and Greenland, and by Reznicek and Ford (2002) in the Flora of North America treatment. These authors found only gradual variation within C. saxatilis s. lat. (incl. C. miliaris) and concluded "that these segregates represent elements in a continuum rather than discrete taxa".
We (Egorova 1999 and in comment, Elven) tentatively draw different conclusions about the combined morphological and geographical pattern. We rather follow Hultén's views with two modifications. The majority of northwestern European C. saxatilis are comparatively small-grown plants with only one male spike and one or two short, subsessile female spikes. They grow in firm "lawns" of calcareous fens in the northern boreal and alpine parts. The tall-grown C. saxatilis of northern Siberia and northwestern North America (subsp. laxa), with often two male spikes, distinctly pedunculate and often pendant female spikes, and more beaked perigynia, would not have been recognized as C. saxatilis in most parts of northern Europe but rather perhaps as C. stenolepis Less. (see Excluded taxa). Moreover, subsp. laxa is, in boreal and low arctic sites, more often a plant of swamps with a soft 'lawn', ditches, water margins, often growing in shallow water, and not distinctly basiphilous. The morphological and geographical pattern may be represented as two subspecies: subsp. saxatilis in northwestern Europe, subsp. laxa elsewhere. The northwestern European plant (C. saxatilis s. str.) may be a Pleistocene depauperate isolate from the more widespread arctic-boreal plant. However, some material from northernmost mainland Europe (Norway and Russia) conform better to subsp. laxa, and the subsp. laxa of Svalbard, Greenland, and northeastern Canada is not nearly as pronounced in its features as the Asian and Berinfgian plant. Features like these may support the "gradual variation" of Reznicek and Ford (above).
The main difference between our and Hultén's alternatives is the treatment of the arctic North Atlantic plants. Hultén and Fries (1986) assigned them to C. saxatilis s. str. but, even if short-grown, the plants of Greenland and Svalbard resemble subsp. laxa in other characters. Plants from Novaya Zemlya (Hultén's "laxa") and from Svalbard and northern Greenland (Hultén's "saxatilis" s. str.) are morphologically inseparable. They may represent intergradation between "saxatilis" s. str. and "laxa" but we rather see them as an arctic western extension of northern Asian "laxa". This may be the reason why Hultén assigned the similar Ellesmere Island plant to subsp. saxatilis, as the plants in the more southern parts of the Canadian Arctic are extensions from the much more tall-grown North American "laxa". We include these northern Greenland and Ellesmere plants in subsp. laxa.
- Carex [3309,genus]