Description:
This native perennial fern is 1-3' tall, forming loose clusters of deciduous
leaves. The light green leaves are bipinnate-pinnatifid, erect to ascending,
and about one-third as wide as long. In overall shape, the compound leaves are
deltoid-lanceolate, ovate-lanceolate, or lanceolate; each compound leaf has
15-30 pairs of leaflets along its rachis (central stalk), terminating in a
slender pinnatifid tip. The lowermost leaflets are only slightly shorter than
the middle leaflets. Each leaflet has 10-20 pairs of subleaflets, becoming
pinnatifid toward its tip. Individual subleaflets are linear-lanceolate to
narrowly lanceolate in shape; they are pinnatifid with short oblong lobes. The
lobes of the subleaflets are bluntly toothed. The slender stipe of each
compound leaf is 4-8" long and usually yellowish green; it is sometimes
slightly hairy or scaly. The rachis is light green to yellowish green; like the
stipe, it is sometimes hairy. The upper surface of each compound leaf is
usually hairless, while the lower surface is hairless to slightly pubescent.
Along the margins of the subleaflets (on their undersides), there are small
cup-shaped indusia containing the sporangia (spore-bearing structures). An
indusium is formed in part by a tooth of the subleaflet folding underneath
itself. The sporangia and cup-shaped indusia develop during the summer or fall.
Their spores are distributed by the wind. The root system is rhizomatous and
fibrous. This fern often forms vegetative colonies.
Cultivation: The preference is partial sun to light
shade, mesic conditions, and a somewhat acidic soil containing sand (or
sandstone) and loam. In some northern areas (e.g., in New England), this fern
will grow in open areas and can spread aggressively, but in most areas of
Illinois is prefers some shade and is less aggressive. The leaves are
attractive from late spring to mid-summer, but become more ragged in appearance
later in the year. 
Range &
Habitat: Hay-Scented Fern is rare in Illinois, which lies at the
western limit of its range (see
Distribution
Map). In Illinois, habitats are restricted to sandstone ravines, shaded
sandstone cliffs, and thinly wooded sandstone bluffs along rivers. This fern is
found in high quality habitats in Illinois, although in areas further to the
east it is often found in disturbed areas. Sometimes this fern is cultivated in
gardens.
Faunal Associations:
Information about floral-faunal relationships is limited. Where White-Tailed
Deer are abundant, this fern has a tendency to increase in abundance because it
is not preferred as a food source. Where sizable colonies of plants are
present, this provides significant cover for wildlife. Otherwise, the
ecological value of this fern to wildlife appears to be low.
Photographic Location: A garden at the Arboretum of
the University of Illinois in Urbana, Illinois.
Comments: This is the only fern of its genus in
midwestern and northeastern United States. It is unique because of the
cup-shaped indusia and folded marginal teeth that are associated with the
spore-bearing structures. Generally, the Hay-Scented Fern is a lighter shade of
green and more lacy in appearance than many other ferns. Compared to the common
Cystopteris protrusa (Fragile Fern), it is larger in size and its leaves
and leaflets have more slender tips. Compared to the Athyrium
filix-femina (Lady Fern), it is smaller in size and its spore-bearing
structures are circular in shape, rather than forming short curved lines. The
common name derives from the hay-like scent of the drying leaves during late
summer or fall.