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Brittle maidenhair
Adiantum tenerum

Copyright by: Keith Bradley

General Landscape Uses: A delicate accent fern on exposed moist limestone in rock gardens and on the banks of water features such as natural pools. Identified by Fair Child Tropical Botanic Garden as a native that does especially well in shade in this brochure.

Ecological Restoration Notes: Limited to exposed moist limestone in rockland hammocks with constantly high humidity. The lowered water table in Miami-Dade County makes this a difficult species to incorporate into restoration projects.

Availability: Grown by enthusiasts.

Description: Medium herbaceous fern with delicate leaflets (pinnae).

Dimensions: About 12-18 inches in height. About as broad as tall.

Growth Rate: Moderate.

Range: Miami-Dade County; disjunct in central and northern peninsular Florida; West Indies, Central America and Venezuela.

Plant Map Map of select IRC data from peninsular Florida.

 Map of suggested ZIP codes from South Florida north to southern Brevard, Osceola, Polk, and Pasco counties.

 Map of ZIP codes with habitat recommendations from the Monroe County Keys north to Martin and Charlotte counties.

Habitats: On moist limestone in rockland hammocks.

Soils: Moist limestone rock, with or without an accumulation of humusy material.

Nutritional Requirements: Moderate; can grow in nutrient poor soils, but needs some organic content to thrive.

Salt Water Tolerance: Low; does not tolerate flooding by salt or brackish water.

Salt Wind Tolerance: Low; salt wind may burn the leaves.

Drought Tolerance: Low; requires moist substrate and high humidity and is intolerant of long periods of drought.

Light Requirements: Light shade.

Flower Color: N/A.

Flower Characteristics: There are no flowers; the plants reproduce by spores.

Flowering Season: All year.

Fruit: Inconspicuous spores.

Horticultural Notes: Can be grown from spores.

References: Miami-Dade County Landscape Manual (2005).

Comments: In the right situations, this rock-loving fern will recruit readily in the garden. It is listed as endangered by the state of Florida.

Copyright by: Keith Bradley

Copyright by: Keith Bradley

Copyright by: George D. Gann
in habitat, Dominican Republic, 2011

Copyright by: George D. Gann
in habitat, Everglades National Park, Florida, 2005

Copyright by: Keith Bradley

Copyright by: Keith Bradley

Other data on Adiantum tenerum available from:

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