in Franklin,Narr. Journey Polar Sea 767. 1823
Plants on rock. Stems decumbent to erect, or creeping, few to many branched; scales colorless or brownish, concolored or bicolored, ovate, lanceolate or linear, margins entire. Leaves dimorphic, scattered or densely tufted; fertile leaves 5–25 cm; sterile leaves 3–20 cm, shorter than fertile leaves. Petiole dark brown proximally, light brown to green distally, with single longitudinal groove adaxially, scaly, with single vascular bundle. Blade deltate, lanceolate to elliptic, 2–4-pinnate, somewhat leathery or herbaceous to membranaceous, abaxially glabrous, adaxially glabrous or sparsely pubescent, dull to somewhat lustrous, not striate; rachis straight. Ultimate segments of blade short-stalked or sessile, free or adnate to midrib; stalks dull, green; segments of sterile leaves ovate, elliptic, obovate, or fan-shaped, usually less than 4 mm wide, margins plane, dentate or shallowly to deeply cut; fertile segments strongly differentiated from sterile segments, lanceolate to linear, usually less than 2 mm wide, margins reflexed to form false indusia extending over entire length of segments, at first covering young sporangia, often becoming plane at maturity. Veins of ultimate segments usually obscure, free, pinnately branched and divergent distally. False indusia greenish to brown, broad, clearly marginal, usually concealing sporangia. Sporangia scattered along veins on abaxial leaf surface, often intermixed with farina-producing glands, containing 64 spores. Spores yellow, tetrahedral, trilete, verrucose, equatorial flange absent. Gametophytes glabrous. x = 30.
Temperate regions, North America, South America, Eurasia.
Species 8–11 (4 in the flora).
|1||Stems 1–1.5 mm diam., creeping, few-branched; leaves scattered along stems, delicate and ephemeral; petioles mostly dark brown in proximal 1/2–2/3, greenish distally; often in calcareous habits.||Cryptogramma stelleri|
|1||Stems 4–20 mm diam., decumbent to erect, many branched from base; leaves strongly tufted, herbaceous to somewhat leathery, present throughout growing season; petioles dark brown in proximal 1/8 or less; mostly of noncalcareous habitats.||> 2|
|2||Blades herbaceous, thin, translucent when dried, shed in autumn, not persistent; hydathodes on dried leaves superficial; hairs absent from adaxial leaf surface.||Cryptogramma cascadensis|
|2||Blades somewhat leathery, opaque when dried, green and persistent over winter; hydathodes on dried leaves sunken below surface; hairs small, appressed, cylindric, present in grooves of petiole, costae, and costules of adaxial leaf surface.||> 3|
|3||Segments oblong to ovate-lanceolate, with 6–12 or more teeth or shallow lobes; sterile leaves 2–3-pinnate.||Cryptogramma acrostichoides|
|3||Segments obovate, with 2–6 deep lobes; at least some sterile leaves 3–4-pinnate.||Cryptogramma sitchensis|