Adiantum capillus-veneris Linnaeus

Venus's-hair fern, southern maidenhair

Etymology Capillus is from the root word for hair; veneris refers to the goddess Venus. Thus it is the Venus-hair fern.
Description Rhizome: short-creeping, branching, slender, scales golden brown to medium brown, iridescent, margins entire or occasionally with single broad tooth near base.
Frond: 30 cm high by 15 cm wide, deciduous, monomorphic, blade/stipe ratio: 3:2.
Stipe: dark purplish to nearly black, grooved above, scaly at base, glabrous in upper portion, 2 mm diam., vascular bundles: 1 or 2.
Blade: 2-pinnate or sometimes more at the base, ovate or triangular, with a terminal pinna similar to the terminal pinnules of the pinnae, membranaceous, glabrous.
Pinnae: 7 to 9 pair, lanceolate, to 8 cm, anadromous in plan; pinnules fan-shaped, rhombic, or round with marginal teeth; costae dark color merging gradually into the lamina; margins fertile lobed, sterile toothed; veins free, forking.
Sori: sporangia, submarginal, indusium: false, inrolled margins, oblong at the ends of segments/pinnules, sporangia: yellow or yellowish brown, maturity: spring to summer.
Culture Habitat: moist calcareous cliffs, banks, and ledges along streams and rivers, walls of lime sinks. Distribution: cosmopolitan in warm-temperate and subtropical regions. Hardy to -15°C, USDA Zone 7.
Synonyms
Adiantum capillus-veneris var. modestum (L. Underwood) Fernald
Adiantum capillus-veneris var. protrusum Fernald
Adiantum capillus-veneris var. rimicola (Slosson) Fernald
Adiantum affine Willd.
Adiantum capillus-veneris
Adiantum capillus-veneris. Frond with pinnules more incised than typical.  Photo © Shirley Denton, from her web site, with permission.
Adiantum capillus-veneris
Adiantum capillus-veneris. Segments.  Illustration by Edgar Paulton, from How to Know the Ferns and Fern Allies, John T. Mickel, © 1979 Wm. C. Brown Co.
Adiantum capillus-veneris
Adiantum capillus-veneris. a) frond and rhizome, b) fertile pinnule.  Illustration by V. Fulford from Ferns and Fern Allies of Canada, William J. Cody and Donald M. Britton, 1989, © Agriculture Canada, used with permission.
Adiantum capillus-veneris
Adiantum capillus-veneris. Segments with transparent false indusia and near ripe sori.  Scan: Tom Stuart
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