Flora of the Southeastern United States
2022 Edition


Data mode


Sign up


Dryopteris Adanson. Woodfern, Shieldfern.

Key to Dryopteris

A genus of about 400 species, nearly cosmopolitan, but concentrated in temperate Asia. Sessa, Zimmer, & Givnish (2012) discuss the phylogeny and biogeography of Dryopteris; the clades shown in the key are from their work.

ID notes: Dryopteris and Athyrium are often confused when not fertile; they can be easily distinguished by breaking off a leaf and counting vascular bundles (which will appear as thread-like strands). Dryopteris has 5 and Athyrium has 2. Many Dryopteris species will hybridize with one another to form sterile hybrids. Whenever two or more Dryopteris species are found growing together, there is a good chance that hybrids are present. Hybrids generally show intermediacy between the two parents, and have abortive sporangia or spores.

Ref: Hoshizaki & Wilson (1999); Kees & Weakley (2018) In Weakley et al. (2018b); Kramer & Green (1990); Montgomery (1982); Montgomery & Paulton (1981); Montgomery & Wagner (1993) In Flora of North America Editorial Committee (1993b); Sessa, Zimmer, & Givnish (2012); Umstead & Diggs (2018); Wyatt (2020). Show full citations.

Show in key(s)

Show parent

Show children

Your browser does not support SVGs

Hover over a shape, letter, icon, or arrow on the map to see what it means. Data for arrows not developed for genera and families which may have species only occurring outside the flora area.

image of plant© Gary P. Fleming | Original Image ⭷
image of plant© Alan M. Cressler | Original Image ⭷
image of plant© Ward, Scott | Original Image ⭷
image of plant© Louis Imbeau, some rights reserved (CC BY), uploaded by Louis Imbeau source | Original Image ⭷
image of plant© Gary P. Fleming | Original Image ⭷
image of plant© Bruce A. Sorrie | Original Image ⭷