040105 Equisetum arvense L.
- L., Sp. Pl.: 1061 (1753). Lectotype (BM-000062951): Europe. Clayton 341 (Jonsell and Jarvis 1994: 148). Jonsell and Jarvis argued that a specimen (LINN 1243.4) previously designated as lectotype by Hauke (1966) may be a post-1753 acquisition, whereas their proposed element with certainty is pre-1753.
Geography: Circumboreal-polar.
Notes: Schönswetter, Elven, and Solstad: Some authors consider the low-grown arctic-alpine plants of Equisetum arvense a subspecies characterized by the spike-bearing stems remaining through summer and developing green branches, and with branches with fewer angles (3 vs. 4). Others see them just as arctic and alpine modifications. Øllgaard (2000) reluctantly accepted subspecies. Both Tzvelev (PAF proposal) and Elven (1994) accept subspecies, but Elven has noted the wide range reported for the arctic-alpine race in European Russia and Siberia, and also in North America, which contrasts with its restriction to high alpine and arctic parts of central and northwestern Europe and Greenland. Different criteria seem to have been applied in different regions. Schönswetter et al. (2001) argued for acceptance of a subspecies, based on several characters. Elven and Solstad investigated the Icelandic (ICEL) and Elven partly the Norwegian material (O). They found the two races separable with few or no transitions. We accept two subspecies.
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Source: MPF at Wikispecies
Higher Taxa
- Equisetum [0401,genus]