Athyrium filix-femina subsp. cyclosorum (Rupr.) Christens.
FamilyAthyriaceae — APG family: Athyriaceae
SynonymsAthyrium filix-femina var. sitchense Rupr., Athyrium cyclosorum Rupr.
Common nameroth lady fern
DescriptionUp to 60 cm tall; rhizome chaffy, forming large crown terminating in tuft of fronds; stipe short, chaffy, blade dark green, bipinnate (rarely tripinnate), with highly variable dissection; lowest primary segments shorter than middle segments.
EcologyCommon in woods and lowlands of southern shore, at least up to 1,200 meters, very rare northward, the northernmost localities being at hot springs. A. filix-femina described from Europe, subsp. cyclosorum from Unalaska and Kodiak.
Specimens from exposed places have broader, blunter, less dissected pinnules, and are usually sterile [f. Hillii (Gilb.) Butt.; A. cyclosorum f. Hillii Gilb.]; such specimens are sometimes mistaken for Dryopteris filix-mas. Alaskan plant has nearly round sori, and is therefore regarded as a race of the typical plant, which has oblong sori; variation in Alaska, however, corresponds to that in other parts of range. Broken line on circumpolar map indicates range of subsp. filix-fémina.
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.