Sensitive Fern (Onoclea sensibilis) Linnaeus, 1753 |
Synonyms: Calypterium sensibile, Onoclea augescens, Onoclea obtusilobata, Pterinodes sensibile, Ragiopteris obtusilobata, Riedlea sensibilis |
Onoclea sensibilis is native to eastern North America (Map), and East Asia, including the Russian Far East, and Korea; introduced in western Europe. It grows in moist or soggy soils in shaded areas, but can tolerate dryer conditions and exposed sites; in swamps, wet meadows, marshes, riverside thickets, or woodlands; 0-1,500 m. Often forms colonies, and readily colonizes disturbed areas. A medium to large-sized deciduous perennial fern. The sterile fronds (30-35 cm) are bright, yellow-green, and coarsely divided; with black petioles; 5-11 pinnae per side. The fertile fronds are black at maturity, oblong, 7-8 cm; sori are clustered on the upright fertile fronds. The vernacular name implies susceptibility to even a light frost.