| Notes | Elven and Solstad: Authors concerned with Greenland have, at least as late as Feilberg (1984b), accepted two varieties of Equisetum sylvaticum - var. sylvaticum and var. pauciramosum - the latter more low-grown, less branched with less rough branches, and more northernly distributed. Similar plants occur in the northern parts of Europe, Siberia, Alaska, and Canada. Porsild (1951, 1975) accepted var. pauciramosum for the Yukon Territory. The differences between the arctic plants and the more southern ones are rather impressive and do not only concern size. However, there is yet no circumpolar evaluation supporting two races, and the variation may be clinal. We have compared some material and do not find a discontinuity in the characters, especially not in the most diagnostic one reported (rough vs. smooth branches). We do not accept the races for the Checklist. |