[3] The sterile and fertile fronds of Onoclea sensibilis have independent stalks originating from the same rhizome, quite different from other ferns.

[4] The bright, yellow-green trophophylls (sterile fronds) are deeply pinnatifid and are typically borne at intervals along the creeping rhizome.

[8] The sporophylls (fertile fronds) are smaller, 20–45 cm (7.9–17.7 in) in length,[8] non-green at maturity and have very narrow pinnae.

Sori are typically bilaterally symmetrical, though leaf forms have been observed with pinnae fertile only on a single side of the rachis.

Other differences include a delayed formation of the osmiophilic crest and during sperm release the cap cell removes intact, as opposed to forming a pore or collapsing altogether.

[12] The small fertile margins, that in live-form held spore in tightly rolled structures, maintain their dry, leathery shape over winter.

Subsequent gametophytes are unisexual in early development, favoring cross-fertilization, later becoming bisexual to ensure species survival.

It tolerates extremely wet soils, appearing in soggy ground or at the very edge of water in shade or sun.

A fifty-seven million year old fossil of Paleocene epoch flora shows specimens virtually identical to modern samples.

Its growth clusters attract local fauna where small wildlife find habitat,[17] deer bed upon its dense mat[19] and in winter wild turkeys use the fertile spore stalks as a secondary food source.

[5][2] Nutrient beneficial ectotrophic mycorrhizal associations may occur in Onoclea sensibilis, Pteridium aquilinum and Adiantum pedatum located in oak and hickory forests.

In one forest setting, a decade long decline was noticed following even single-cut tree felling operations.

Onoclea sensibilis hosts insects, fungi, bacteria and even a parasitic vine, Cuscuta gronovii (scaldweed), that can overgrow and constrict it.

In a multi-year study the weedy presence of O. sensibilis at rice paddy fields and a means to convey the bacterium (rainfall runoff) implicated it as the source of bacterial blight outbreaks when paired with enabling environmental conditions.

Ingesting any part of the plant introduces thiaminase enzymes and phytoecdysteroid hormones which can disrupt an insect's molting cycle, preventing its full development.

[31] Its summaries, however, frequently include precautionary statements that ferns, in general, may contain natural carcinogens and/or the enzyme thiaminase, the latter being dangerous in high concentration.

[31][17] Historically, some Native American peoples have consumed Onoclea sensibilis without apparent distress; see Food uses in this article.

[31] The Iroquois treated Onoclea sensibilis as an early springtime vegetable, prepared like spinach, the fiddleheads cooked and "seasoned with salt, pepper or butter" (Waugh, 1916).

[16] [31] Historically, Native American peoples used Onoclea sensibilis for oral and topical indigenous treatments.