Adiantum aethiopicum

Pteridaceae

Adiantum aethiopicum L.

Link to Australian Plant Name Index for publication details and synonyms: https://id.biodiversity.org.au/name/apni/76279

Maidenhair Fern

Rhizome creeping, to 3 mm diam., stoloniferous; stolons wiry, c. 1.5 mm diam.; scales thin, yellow, transparent, broadly triangular, entire, often spirally curled. Fronds densely tufted, or sometimes scattered along stolons, to 75 cm long. Stipe to 40 cm long, glossy, glabrous, red-brown, bearing conspicuous basal scales similar to those of the rhizome. Lamina 3-pinnate, ovate to triangular, 12–40 cm long, 5–23 cm wide. Pinnae narrowly triangular. Pinnules round to flabellate; distal margin sometimes shallowly lobed; lobe margins entire or obscurely dentate when sterile; stalks not articulated. Sori 1–5 along the distal margins, 1 (–2) per lobe; soral flaps reniform to (sub)lunate, usually at the base of a broad shallow sinus on the pinnule margin. Spores 64 per sporangium, with largest diam. (34.6–) 41.1 (–53.6) µm. 

Widespread across temperate and subtropical Australia with outlying populations in NE QLD. Also widespread in temperate and subtropical areas of the old-world.

Terrestrial in the understorey of sclerophyll woodland. This species is not usually found in rainforest in tropical Queensland.

This is a commonly cultivated ornamental fern in tropical, subtropical and temperate areas. It is suited to cultivated in a semi-shaded part of the garden or in a greenhouse. It is suited to cultivation in the ground or in a container planted in a free-draining but moisture retentive terrestrial growing medium. A tidy plant can be produced by removal of old fronds once per year just prior to the emergence of new fronds in spring. New plants are produced by spores or by division of offsets which form upon the roots which will emerge from the draininage holes of a pot or through the lining of a coir lined hanging basket.

Key to some Adiantum species of tropical Australia.

1a. Fronds pinnate = Adiantum philippense

1b. Fronds bipinnate or higher = 2

2a. Pinnules flabellate to rounded = 3

2b. Pinnules obliquely oblong to rhomboid = 5

3a. Soral flaps broadly attached to lamina and situated on the ends of lobes with incisions between them = Adiantum capillus-veneris

3b. Soral flaps reniform and narrowly attached to lamina and situated in incisions of the lamina margin with lobes between them = 4

4a. Rhizome long creeping, rhizome scales translucent with entire margins, plants stoloniferous and spreading, pinnae pale bright green when mature = Adiantum aethiopicum

4b. Rhizome short creeping, rhizome scales opaque with denitculate margins, not stoloniferous plants tufted, pinnae dark green when mature = Adiantum atroviride

5a. Rhizome long creeping, fronds scattered = 6

5b. Rhizome not long creeping, fronds tufted = 7

6a. Primary pinnae progressively reducing in length from base to apex of frond resulting in a triangular lamina = Adiantum formosum

6b. Primary pinnae equal in length resulting in an ovate lamina = Adiantum silvaticum

7a. Pinnae soft and membraneous with fine black hairs on the undersurface, root tubers present, often proliferous, stipe smooth = Adiantum diaphanum

7b. Pinnae herbaceous to coreaceous with white hairs, root tubers absent, not proliferous, stipe not smooth = Adiantum hispidulum