Etymology Greek: kryptos, hidden + gramme, line. The reflexed leaf margin hides the line of sori.

Description Rhizome: erect to creeping, scales colorless or brownish, concolored or bicolored, ovate, lanceolate or linear.
Frond: deciduous or evergreen, dimorphic.
Stipe: dark brown proximally, light brown to green distally, with single longitudinal groove above, scaly, vascular bundles: 2.
Blade: 2-3 pinnate, deltate, lanceolate to elliptic, somewhat leathery or herbaceous to membranaceous, glabrous or sparsely hairy above, glabrous below.
segments sterile: toothed, veins free.
Sori: scattered along veins, submarginal, indusium: false, strongly enrolled, sporangia: yellow.