Athyrium thelypterioides  (Asplenium acrostichoides, Deparia a.) silvery glade-fern Aspleniaceae ATTH; R;


Athyrium thelypterioides.USDAplants

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner’s Sons, New York. (Accessed 5/2014).

Athyrium thelypterioides is a fern from a short, creeping rhizome. 

Leaves 35-110 cm; blade longer than stalk, 13-22 cm wide, once pinnate and pinnately lobed, tip sharply long-pointed, pinnately divided, basal leaflets reduced and pointing downward, midrib (rachis) hairy, slightly scaly, hairy, leaflets 15-20 per side, stalkless, tips long-pointed, deeply, regularly lobed, lobes to 1.3 cm long, 0.6 cm wide, oblong, round-tipped with margins entire to barely toothed. 

Spore cases elongate, to 0.2 cm, 3-7 pairs per side, along pinnate veins of leaflet lobes, silvery with yellowish hairs, becoming pale brown (Cobb 1963). 

Wetland status: FAC. 

Frequency in NYC: Very infrequent. 

Origin: Native to NYC. 

Habitat: Moist woods in rich soil pH 4.5-7, tolerant of shade, intolerant of fire, salt, anaerobic soil, drought (USDA, NRCS 2006).