[2] Members of Aspidotis are small ferns, with shiny, tufted fronds generally less than 35 centimeters long (although A. schimperi may be larger[2]).

[5] As of January 2020[update], the Checklist of Ferns and Lycophytes of the World recognized five species,[6] including one identified as a fertile interspecific hybrid.

Ferns in this genus grow in a variety of conditions, from low woodland slopes,[2] to chaparral, to higher-elevation ridges, to marginal habitats like rocky crevices and the bases of boulders.

[8] A. carlotta-halliae and the West Coast populations of A. densa are commonly associated with these ultramafic soils but are not restricted to them.

In all cases, the name is derived from Greek, and refers to the distinctive shield-like false indusium found especially in A. californica.