Adiantum tenerum


Prodr. 135. 1788

Common names: Brittle maidenhair
Treatment appears in FNA Volume 2.
Stems short-creeping; scales bicolored, centers dark reddish brown, margins pale tan, erose-ciliate. Leaves arching or sometimes pendent, closely spaced, 20–110 cm. Petiole 1–3 mm diam., glabrous, occasionally glaucous. Blade trowel-shaped, pinnate, 12–60 × 12–60 cm, gradually reduced distally, glabrous; proximal pinnae 3-pinnate; rachis straight, glabrous, not glaucous. Segment stalks 1–5 mm, with dark color ending abruptly at segment base, terminating in cupulelike swelling at base of segment (unlike any other species of Adiantum in the flora). Ultimate segments fan-shaped or rhombic, about as long as broad; base cuneate; apex rounded or acute, lobed, lobes separated by narrow incisions 0.5 mm wide. Indusia transversely oblong to crescent-shaped, 0.5–2 mm, glabrous. Spores mostly 40–58 µm diam. 2n = 60.

Phenology: Sporulating throughout the year.
Habitat: Restricted to moist, shaded, limestone ledges, sink walls, and grottoes in the flora
Elevation: 0–50 m


V2 434-distribution-map.gif

Fla., e, s Mexico, Central America in Guatemala, Honduras, Nicaragua, Costa Rica, South America in Venezuela.


Adiantum tenerum is readily distinguished from other species in the flora by the ultimate segments conspicuously articulate to the stalks.

Selected References


Lower Taxa


Facts about "Adiantum tenerum"
AuthorCathy A. Paris +
AuthoritySwartz +
Common nameBrittle maidenhair +
DistributionFla. +, e +, s Mexico +, Central America in Guatemala +, Honduras +, Nicaragua +, Costa Rica + and South America in Venezuela. +
Elevation0–50 m +
HabitatRestricted to moist, shaded, limestone ledges, sink walls, and grottoes in the flora +
IllustrationPresent +
Illustration copyrightFlora of North America Association +
IllustratorJohn Myers +
PhenologySporulating throughout the year. +
Publication titleProdr. +
Publication year1788 +
ReferenceNone +
Source xml grained fna xml/V2/V2 434.xml +
Taxon familyPteridaceae +
Taxon nameAdiantum tenerum +
Taxon parentAdiantum +
Taxon rankspecies +
VolumeVolume 2 +