Northern maidenhair

Conservation Status

IUCN Red List

not listed

NatureServe

N5 - Secure
SNR - Unranked

Minnesota

not listed

Wetland Indicator Status

Great Plains

FAC - Facultative

Midwest

FACU - Facultative upland

Northcentral & Northeast

FACU - Facultative upland

Description

Northern maidenhair is a 12″ to 24″ tall, erect, perennial fern that rises on a single frond or a few fronds from a short, creeping rhizome and black, hair-like roots.

The leaves (fronds) are erect, arching, closely spaced, 15¾″ to 30″ long, and deciduous. The leaf stem (stipe) is purple or purplish-black, grooved, hairless, and occasionally covered with a whitish, waxy bloom (glaucous). It is ⅜″ to 2⅜″ long and divided at the top into two equal branches (rachises) that are arched to bent backwards. The blades are held horizontally, 90° to the stipe, roughly parallel to the ground.

The blade is kidney-shaped to almost circular, 6″ to 11¾″ long, and 6″ to 13¾″ wide. Each rachis has 2 to 9 primary leaf segments (pinnae) attached to the upper side each rachis. The pinnae closest to the stipe are the largest and have mostly 15 to 35 widely spreading leaflets (pinnules). The pinnae become progressively shorter as they approach the tip.

The pinnules are alternate, short stalked, oblong to nearly rectangular, ½″ to ⅞″ long, and 3 ⁄16″ to ⅜″ wide, about 3 times as long as wide. The terminal and lowest pinnule is fan-shaped. The main vein is along the lower margin. The lateral veins are easily seen. The lower margin is unlobed, untoothed, and slightly curved. The upper margin is lobed. The lobes are separated by narrow sinuses, and toothed with rounded teeth. The upper surface is green and hairless. The underside is green and is not covered with white powder. They repel water, so that after a rain they look dry with water beads on the surface.

On fertile pinnules the upper margin is bent backward into a membranous flap (indusium) on which oblong, spore-bearing structures (sporangia) are borne in a compact cluster (sorus). There are 64 yellow to light brown spores per sporangium. Spores are produced from July to September.

Height

12″ to 24″

Similar Species

Habitat

Moderate moisture. Deciduous woods. Shade.

Ecology

Sporulation

July to September

Pests and Diseases

Use

Distribution

Sources

2, 3, 5, 7, 24, 28, 30, 83.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu. Accessed 10/16/2026.

Midwest Herbaria Portal. 2026. https://midwestherbaria.org/portal/index.php. Accessed 10/16/2026.

Adiantum pedatum L. in Bánki, O., Roskov, Y., Döring, M., Ower, G., Hernández Robles, D. R., Plata Corredor, C. A., Stjernegaard Jeppesen, T., Örn, A., Pape, T., Hobern, D., Garnett, S., Little, H., DeWalt, R. E., Miller, J., Orrell, T., Aalbu, R., Abbott, J., Abreu, C., Acero P, A., et al. (2026). Catalogue of Life (2026-08-26 XR). Catalogue of Life Foundation, Amsterdam, Netherlands. https://doi.org/10.48580/dgyy9

Tryon, R. M. (1980). Ferns of Minnesota (2nd ed., revised). University of Minnesota Press.

Smith, W. R. (2023). Ferns and lycophytes of Minnesota: The complete guide to species identification (R. W. Haug, Photogr.). University of Minnesota Press.