Woodwardia, commonly known as chain ferns or netted-chain ferns, is a genus of large ferns in the family Blechnaceae (order Polypodiales, suborder Aspleniineae). The genus was first described by the English botanist James Edward Smith in 1793 and named in honour of the English botanist Thomas Jenkinson Woodward.
Plants in this genus are robust, terrestrial ferns native to warm temperate and subtropical regions of the Northern Hemisphere, with a range spanning North America, Europe, Asia, and the Macaronesian islands. Fronds are typically large, ranging from 50 to 300 cm in length depending on the species, and are characterized by the netted (areolate) venation pattern from which the common name "netted-chain fern" derives.
When broadly circumscribed, the genus comprises about 15 species plus natural hybrids. Under the Pteridophyte Phylogeny Group classification of 2016 (PPG I), two monotypic segregate genera are maintained separately: Anchistea (containing W. virginica) and Lorinseria (containing W. areolata), though many sources still treat all species under Woodwardia. The genus has an ancient lineage — its fossil record extends back to the Paleocene epoch.
Notable species include Woodwardia radicans (European chain fern), Woodwardia fimbriata (giant chain fern of western North America), and Woodwardia unigemmata (one-bud chain fern of East Asia), the last of which is cultivated as an ornamental for its distinctive proliferous buds on the frond surface.
Etymology
Woodwardia was described and named by the English botanist James Edward Smith in 1793, honouring his contemporary Thomas Jenkinson Woodward (1745–1820), an English botanist and mycologist.
Distribution
The genus is native to warm temperate and subtropical regions of the Northern Hemisphere, including North America (both eastern and western), Europe (Atlantic islands and southern Europe), and Asia (East and Southeast Asia, including Japan and China).
Taxonomy Notes
The genus has historically been broadly circumscribed to include approximately 15 species. The Pteridophyte Phylogeny Group (PPG I, 2016) separates the monotypic genera Anchistea (W. virginica) and Lorinseria (W. areolata), though Plants of the World Online and many treatments still accept a broad Woodwardia. The genus belongs to suborder Aspleniineae (eupolypods II) of the order Polypodiales.
