Mostly medium-sized ferns, with slender wide-creeping hairy rootstocks and scattered 2-3-pinnate erect leaves, 2°-6° high. Sori marginal, terminal upon the free veinlets, the sporanges clustered upon a very small receptacle within a special cup-shaped indusium formed in part of the more or less modified reflexed segment of the leaf-margin. [Name in honor of August Wilhelm Dennstaedt.]

About 50 species mainly of tropical and subtropical regions. Type species: D. flaccida (Forst.) Bernh.

1. Dennstaedtia Punctilobula (Michx.) Moore. Hay-Scented Fern

Fig. 29

Nephrodium punctilobulum Michx. Fl. Bor. Am. 2: 268.

1803. Dicksonia pilosiuscula Willd. Enum. 1076. 1809. Dicksonia punctilobula A. Gray, Man. 628. 1848. Dennstaedtia punctilobula Moore, Ind. Fil. xcvii. 1857.

Rootstock slender, extensively creeping, not chaffy. Stipes stout, chaffless, usually castaneous at the base; blades 1°-3° long, 5'-9' wide, ovate-lanceolate to deltoid-lanceolate, acute or acuminate, frequently long-attenuate, usually 3-pinnatifid, thin and delicate, the rachis and under surface minutely glandular and pubescent; pinnae numerous, lanceolate, the segments ovate to oblong, close and deeply lobed, the margins with oblique rounded teeth; sori minute, each on a recurved tooth, usually one at the upper margin of each lobe; sporanges few, borne within the delicate cup-shaped indusium.

In various situations, most abundant on open hillsides, Nova Scotia and New Brunswick to Ontario and Minnesota, south to Georgia, Alabama and Missouri. Ascends to 5600 ft. in Virginia. Aug. Called also Fine-haired-fern, Hairy dicksonia, Boulder-fern.