New World bird's-nest fern, American bird's-nest fern

Roots proliferous. Stems erect, unbranched; scales brown throughout, narrowly lanceolate, 5--10 × 1--1.5 mm, margins entire. Leaves monomorphic. Petiole vestigial. Blade linear, oblanceolate, simple, (10--)20--40(--70) × 3--8 cm, thick, glabrous; base gradually tapered; margins entire to irregularly crenate; apex attenuate, not rooting. Rachis green throughout, dull, glabrous. Veins numerous, free, mostly immersed. Sori parallel to each other, nearly perpendicular to midrib. Spores 64 per sporangium. 2 n = 144.

Rotten logs and stumps; 0--50 m; Fla.

Asplenium serratum is found rarely in southern peninsular Florida, where it is at the extreme edge of its tropical American range. This large simple-leaved spleenwort is called "American bird's-nest fern" because of its superficial resemblance to the Old World A . nidus Linnaeus, which is regularly grown in temperate conservatories. Asplenium serratum is unusual in having roots with abundant, matted hairs rather than scattered hairs as found in other species.