Equisetum arvense L.
FamilyEquisetaceae — APG family: Equisetaceae
DescriptionRhizome creeping, with ovoid tubers and dark felt; spring phase brown, lacking chlorophyll, usually branchless with obtuse cones, soon withering; summer phase very different, with sterile, erect, depressed, or prostrate 3-5-angled stem, with sim- ple or forking branches.
EcologyExtremely variable in habitat and soils, as well as in form; occurs sometimes as weed. Described from Europe.
Two variations deserve special attention. Var. boreale (Bong.) Ledeb. [E. boreale Bong., E. arvense subsp. boreale (Bong.) Love], with simple, long, spreading, 3- angled branches, is common. Especially in the north, the fertile spring phase sometimes develops green branches from the nodes; such plants have been called E. Calderi Boiv. The taxonomic value of these variations is unclear.
Hultén's Flora About

This is a digital representation of Eric Hultén’s ‘Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants’, which was published by Stanford University Press in 1968. The book was digitized by C. Webb (at UAMN) as part of the Flora of Alaska project, with funding by the US NSF (Grant 1759964 to Ickert-Bond & Webb), and with permission of Stanford University Press. Data and images © 1968 Board of Trustees of the Leland Stanford Jr. Univ. Usage licence: Creative Commons BY-NC-SA 4.0. NB: You may find OCR errors; please refer to the hard-copy if in doubt.