Struthiopteris, Latin, from struthio, ostrich, + pteris, Greek, from pteron, a wing, referring to the shape of the pinnae, but the word pteris was used by the ancient Greeks for ferns in general.
Rhizome: erect, forming a vase-like plant, becoming short trunks with age, armoured with black, old stipe bases, appearing braided.
Frond: 150 cm high by 30 cm wide, sterile: deciduous, late-appearing; fertile: appearing midsummer, persisting into winter, infrequently produced, dimorphic, the fertile frond to 40 cm x 6 cm, blade/stipe ratio: 5:1.
Stipe: green, with an expanded base (trophopod), white hairs on sterile frond, also orange-brown scales, vascular bundles: 2, s-shaped, back-to-back, at an acute angle.
Blade: sterile: 1-pinnate-pinnatifid, elliptic, widest one-quarter below apex, abruptly reduced towards the tip, sterile: herbaceous, fertile beady, green young, maturing to dark brown, absent or deciduously hairy below.
Pinnae: 20 to 60 pair, proximal pinnae (several pairs) greatly reduced, sessile; pinnules oblong, blunt, 20--40 pairs per pinna; costae shallowly grooved above, grooves not continuous from rachis to costae; margins entire; veins free.
Sori: round, covered by revolute margins, indusium: vestigial, sporangia: green, maturity: the following spring.
Habitat: moist soil in deciduous and mixed forest, wooded river bottoms, and swamps.
Hardy to -40°C, USDA Zone 2.
handsome, tall, vase-shaped crown of fronds, in dense stands
Osmunda struthiopteris L.
Matteuccia struthiopteris (L.) Todaro var. pensylvanica (Willd.) C.V.Morton
Matteuccia pensylvanica (Willd.) Raymond
Matteuccia struthiopteris (L.) Todaro var. pubescens (Terry) Clute
Onoclea struthiopteris (L.) Hoffm. var. pensylvanica (Willd.) B.Boivin
Pteretis nodulosa (Michx.) Nieuwl.
Pteretis nodulosa (Michx.) Nieuwl. f. pubescens (Terry) Fernald
Pteretis pensylvanica (Willd.) Fernald
Pteretis pensylvanica (Willd.) Fernald f. pubescens (Terry) Fernald
Pteretis struthiopteris (L.) Nieuwl.
Struthiopteris pensylvanica Willd.