Adiantum L.

8 species in AUST. ( 2 endemic, 6 native); all states and territories

Terrestrial ferns. Rhizomes tufted to long-creeping, solenostelic or with a few meristeles, clothed with narrow, black or dark brown, entire or toothed, non-peltate scales which are sometimes paler towards the margin. Stipes not articulated to the rhizome, polished, black or dark brown, clothed near the base with scales, sometimes hairy in the upper parts. Main rhachis grooved above. Lamina 1–4-pinnate, decompound or digitate in the Australian species, glabrous or sometimes clothed with scattered hairs or setae. Ultimate segments dimidiate or flabellate-cuneate, mostly herbaceous, sometimes almost membranous or coriaceous. Veins free, fine, flabellate, branching dichotomously without any main veins. Sori marginal in shallow notches or deep grooves, borne on the lower surface of sharply reflexed marginal lobules. False indusium consisting of the ± reniform, reflexed margin of the frond-segment, opening inwards, bearing and covering the sori (Fig. 17). Sporangia borne along the veins which are continuous into the lobule; the pedicel long, narrow; the annulus including c. 18 thick-walled cells. Spores tetrahedral or sometimes bilateral, smooth, dark, lacking a perispore.