Hay-Scented Fern family (Dennstaedtiaceae)
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.