1Rhizome covered with peltate scales (Subg. Myrmecopteris)
1'Rhizome not covered with peltate scales (Subg. Lecanopteris)
2Rhizome massive, strongly flattened, arched, scales sparse, not completely covering the surface
2'Rhizome hollow, thick, scales dense, covering the surface
3Fronds simple, rhizome little-branched
3'Fronds pinnatifid, rhizome frequently branched
4Rhizome a uniform structure, all branches hollow, scales mostly with a brown centre
4'Rhizome consisting of solid, frond-bearing main branches and hollow, ovate or irregularly shaped, frondless lateral branches, the scales mostly with a blackish centre
5Rhizome and fronds glaucous, naked
5'Rhizome green, with spines, coralloid outgrowths or dense glandular indumentum (lens!), or stipe and rachis with hairs below
6Rhizome with spines or coralloid outgrowths in two rows, replacing fronds; a single internal gallery system; and hollow, protruding phyllopods
6'Rhizome with irregular, dense cover of spines or coralloid outgrowths not replacing fronds; two internal gallery systems; and solid phyllopods
7Rhizome with hollow spines; fronds entire to pinnatifid
7'Rhizome with solid spines or coralloid outgrowths; fronds pinnatifid
8Rhizome with coralloid outgrowths 1-3 cm long
8'Rhizome with spines
9Large plants; rhizome 2.5-3.5 cm thick, with abundant spines; fronds up to 1 m long
9'Smaller plants; rhizome to 2.5 cm thick, with few spines; fronds up to 45 cm long
10Rhizome covered with short hairs and scattered scales, stipe and rachis glabrous, sori round
10'Rhizome glabrous except near apex, stipe and rachis with persistent hairs below, sori laterally flattened
11Fronds simple, sori deeply immersed on lamina
11'Fronds pinnatifid, sori on marginal lobes
12Veins not sclerified, green, sori on stalked, unreflexed lobes
12'Veins sclerified, appearing black; sori on unstalked, reflexed lobes.