Contains 8 accepted taxa overall.

Characteristics
Adiantum L.
MAIDENHAIR FERN
Classification
POLYPODIALES
Adiantum
Citation
ADIANTUM Linnaeus, Sp. Pl. 1094. 1753.
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TYPE: Adiantum capillus-veneris Linnaeus Lectotypified by J. Smith, Hist. Filicum 274. 1875.
Species
Scientific Name Common Name Herbarium Specimens Status Photos
Adiantum anceps DOUBLE-EDGE MAIDENHAIR Not Native
Adiantum capillus-veneris VENUS'-HAIR FERN; SOUTHERN MAIDENHAIR; COMMON MAIDENHAIR Native FACU (NWPL)
Adiantum caudatum TAILED MAIDENHAIR Not Native
Adiantum hispidulum ROUGH MAIDENHAIR Not Native
Adiantum melanoleucum FRAGRANT MAIDENHAIR Native Endangered-State UPL (NWPL)
Adiantum tenerum BRITTLE MAIDENHAIR Native Endangered-State FAC (NWPL)
Adiantum trapeziforme DIAMOND MAIDENHAIR Not Native
Adiantum villosum WOOLLY MAIDENHAIR Native
[Family identification key]
1.  Leaves 1-pinnate, tip of some leaves prolonged with reduced pinnae and a proliferous bud
1.  Leaves usually 2-pinnate, the tip not prolonged, not proliferous
2
2.  Ultimate pinnules 2.5-6 cm long, 1.5-6 cm wide
3
2.  Ultimate pinnules 0.5-2.5 cm long, 0.5-2.5 cm wide
4
3.  Ultimate pinnules subentire with sinuses to 1 mm deep, the lateral pinnules generally broadly ovate, suborbicular, or quandrangular
3.  Ulimate pinnules usually conspicuously incised with sinuses to 5 mm deep, the lateral pinnules generally rectangular
4.  Petiolule or ultimate pinnule stalk 1-5 mm long, often appearing centrally attached to the blade segment; ultimate pinnule usually with some deep sinuses 1/3 or more the length of the segment,
5
4.  Petiolule or ultimate pinnule stalk 0-1 mm long, mostly appearing to be attached to the basal side of the ultimate pinnule; ultimate pinnule lacking sinuses or these <1/5 of the segment length or width
6
5.  Dark color of petiolule or ultimate pinnule stalks extending into base of pinnules, not forming an articulate, cup-like swelling
5.  Dark color of petiolule or ultimate pinnule stalks not extending into base of pinnules, petiolule or pinnule stalks terminating in an articulated, cup-like swelling at base of blade segments
6.  Basal pair of pinnae 1-pinnate; ultimate pinnules 12-25 mm long
6.  Basal pair of pinnae 1- to 4-pinnate; ultimate pinnules 5-12 mm long
7
7.  Rachis hispid; ultimate pinnules with scattered multicellular hairs; false indusia generally round
7.  Rachis strigose; ultimate pinnules glabrous; false indusia crescent-shaped
Genus Synonyms
Synonym Full Citation Basionym Type
Hewardia Hewardia J. Smith, J. Bot. (Hooker) 3: 432. 1841. TYPE: Hewardia adiantoides J. Smith