1Teeth present at the bases of sinuses between pinna- or pinnule-lobes, the teeth projecting out of the plane of the lamina
1'Teeth of this kind lacking
2Fronds simply pinnate with free veins; no unicellular glands on lamina or in sori
2'Fronds mostly bipinnate, their veins forming at least costal aréoles; cylindric glands present
3All axes of the frond bearing copious scales, the smaller ones at least partly clathrate with isodiametric cells
3'Smaller axes of the frond bearing few scales which are not thus clathrate
4Veins in sterile fronds anastomosing copiously; free veinlets in areoles (including those along costae) variously directed and in most species forked
4'Veins anastomosing to form costal areoles which lack free veinlets, or all veins free
5Fertile fronds greatly contracted and bearing indusia
5'Fertile fronds not greatly contracted, or if so lacking indusia
6Sterile fronds simple; fertile ones irregularly deeply lobed; indusia reniform
6'Sterile fronds pinnate; pinnae of fertile fronds linear, with continuous indusia along each side of the costae
7Some thick multicellular hairs present between veins on the upper surface, at least near sinuses between lobes
7'No thick hairs present between veins on upper surface
8Basal basiscopic lobe or pinnule of basal pinnae longer than the other lobes or pinnules
8'Basal basiscopic lobe of basal pinnae much reduced, these pinnae widest at about mid-length
9Fronds not greatly longer than wide
9'Fronds greatly longer than wide, with many pinnae gradually increasing in size downwards
10Veins anastomosing in some species; fertile fronds, if greatly contracted, not bearing very small pinnules
10'Veins all free; fertile fronds bipinnate with very small pinnules, exindusiate
11Pinnae articulate to the rachis, entire or crenate
11'Pinnae not articulate, deeply lobed or pinnate