A Checklist of the Vascular Plants of Washington State
Hosted by the University of Washington Herbarium, Burke Museum
Hosted by the University of Washington Herbarium, Burke Museum
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Dryopteridaceae » Dryopteris expansa
Last updated 5/20/2023 by David Giblin.
Dryopteris expansa (C. Presl) Fraser-Jenk. & Jermy[FNA2, HC2]
northern fern, spreading wood-fern
Publication: Brit. Fern Gaz. 11: 338. 1977.
Origin: Native
selected vouchers: WTU
Notes: FNA2: "Dryopteris expansa is diploid and is one of the parents of D . campyloptera . Where their ranges overlap in eastern Canada, these two species are very difficult to distinguish except by chromosome number. The growth habit ( D . expansa leaves are more erect) is useful in the field. Three hybrids involving D . expansa are known; all are very rare."
References: (none)
Synonyms & Misapplied Names:
Dryopteris assimilis S. Walker
Dryopteris campyloptera (Kunze) Clarkson, misapplied[FNA2]
Dryopteris dilatata (Hoffm.) A. Gray, misapplied[Abrams, Peck]
Dryopteris dilitata (Hoffm.) A. Gray var. americana (Fisch.) Hultén
Nephrodium expansum C. Presl
