Plants terrestrial or rarely on rock. Stems creeping to ascending or erect, slender to stout, sometimes climbing [rarely subarborescent]; scales brown or black. Leaves monomorphic or variously dimorphic, cespitose to scattered. Blades pinnatifid to 1-pinnate, rarely simple or 2-pinnate. Rachis and costae glabrous, scaly, or hairy abaxially. Veins free, often forked. Sori borne on vascular commissures parallel to costae, 1 per side, normally uninterrupted, linear, continuous along length of costa. Spores with perine smooth to variously winged or rugose. x = 28, 29, 31, 32, 34, 36.
Mostly tropical, especially Southern Hemisphere.
Species ca. 220 (3 in the flora).
|1||Leaves strongly dimorphic, fertile leaves notably more erect, longer, and with narrower pinnae than sterile leaves; sterile blades tapering at base.||Blechnum spicant|
|1||Leaves ± monomorphic, fertile leaves only slightly longer and somewhat contracted relative to sterile leaves; sterile blades ± truncate at base.||> 2|
|2||Blades 1-pinnate proximally and pinnatifid distally or pinnatifid nearly throughout, usually less than 50 cm; pinna margins ± entire.||Blechnum occidentale var. minor|
|2||Blades 1-pinnate throughout, usually more than 50 cm; pinna margins ± evenly serrulate.||Blechnum serrulatum|