AspleniaceaeAspleniaceae
GENERA (78) include Ceterach, Diellia, Schaffneria, Holodictyum, Asplenium, Pleurosorus, and Camptosorus.
THE ASPLENIACEAE are an unusually homogenous group of around 700 species, showing many similar morphological features.
SORI are usually elongate, and borne on the lower surface of leaves. They are either covered with an indusium, or found within a pouch formed by the indusium and opposed marginal leaf tissue.
SPORANGIA are thin-walled, and usually long-stalked. The annulus is vertical, well-developed, and interrupted by the stalk.
SPORES lack chlorophyll. They are homosporous,
and borne in groups of (32) 64. Spores are consistently monolete,
and usually ellipsoidal.
STEMS range from stout and erect to slender and long-creeping. They are indurated, and may branch. Stems bear scales and, rarely, also trichomes.
PETIOLES are slender or, more often, coarse. They lack stipules, and have two to several vascular bundles.
LEAVES may be entire, pinnate, or pinnatifid. Circinate in bud, they range from 1 cm to 3 m in length.
VENATION is free, rarely netted.The vascular cylinder is dictyostelic, or (less often) filiform and protostelic.
RHIZOMES are scaly.
THE GAMETOPHYTE is epigeal and photosynthetic. It may be glabrous or bear trichomes. Cordate or elongate, the gametophyte is slightly thickened centrally. Archegonia are borne on lower surface, especially near the sinus. Antheridia are also borne on lower surface, but near the central cushion.
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