| 1 | Base of stipe bearing pale, firmly cylindrical multiseptate hairs. |
| 1' | Base of stipe not bearing such hairs. |
| 2 | Stipe and abaxial surface of rachis densely covered with spreading hairs many of which are septate (see also n. 14) |
| 2' | Stipe above base and abaxial surface of rachis less densely hairy with few septate hairs. |
| 3 | Indusium glandular; scales at base of stipe to 10 x 3 mm |
| 3' | Indusia bearing acicular hairs; scales at base of stipe much smaller |
| 4 | Sessile glands and/or acicular hairs abundant between veins on upper surface. |
| 4' | Sessile glands and acicular hairs lacking or rare between veins on upper surface of pinnae. |
| 5 | Scales on lower surface of costae at most 2 cells wide at base. |
| 5' | Scales on lower surface of costae widened at base. |
| 6 | Stipe-scales thin, less than 1 mm wide above base; lower surface of costae bearing many acicular hairs. |
| 6' | Stipe-scales firm, 1 mm or more wide; lower surface of costae bearing short capitate hairs and glands, acicular hairs lacking or very few. |
| 7 | Pinnae to 2.5 cm long, nearly all deflexed |
| 7' | Pinnae to 5.5 cm long, a few basal ones deflexed. |
| 8 | Pinnae to 25 pairs or more; pinna-lobes mostly entire. |
| 8' | Pinnae 12-18 pairs; pinna-lobes mostly crenate |
| 9 | Upper surface of pinnae lacking acicular hairs between veins |
| 9' | Upper surface of pinnae bearing acicular hairs between veins. |
| 10 | Lower surface between veins, and indusia, lacking acicular hairs |
| 10' | Lower surface bearing copious short erect acicular hairs between veins |
| 11 | Upper surface of pinnae lacking acicular hairs between veins. |
| 11' | Upper surface of pinnae bearing acicular hairs between veins. |
| 12 | Scales on lower surface of costae broadly ovate |
| 12' | Scales on lower surface of costae linear with a ± widened base. |
| 13 | Indusia bearing copious acicular hairs; stipe-scales 3x0.8 mm, firm, with many spherical outgrowths on dorsal surface |
| 13' | Indusia lacking acicular hairs; stipe-scales to 7 x 1.5 mm, thin, smooth dorsally |
| 14 | Sessile glands present on lower surface generally, or at least on costules. |
| 14' | Sessile glands lacking on lower surface except in C. fasciculata which may have a few glands on costae. |
| 15 | Sori distinctly supramedial |
| 15' | Sori medial to inframedial. |
| 16 | Basal half of lower pinnae bearing free or separately adnate pinnules. |
| 16' | At most one free pinnule present at base of largest pinnae. |
| 17 | Many septate hairs present on upper surface of rachis and costae. |
| 17' | Septate hairs absent or rare on upper surface of rachis and costae. |
| 18 | Septate hairs on upper surface of rachis and costae less than 0.5 mm long; stipe-scales 3 mm long |
| 18' | Septate hairs on upper surface of rachis and costae 1 mm or more long; stipe-scales much longer. |
| 19 | Stipe-scales to 10x3 mm, thin; hairs on upper surface of rachis and costae commonly 1-1.5 mm long |
| 19' | Stipe-scales to 7 x 1 mm, rigid, hair-pointed; hairs on upper surface of rachis and costae not over 1 mm long |
| 20 | Sori mainly along one side of a vein, rarely reniform |
| 20' | Sori mainly reniform, distal ones sometimes ± athyrioid. |
| 21 | All pinna-lobes entire. |
| 21' | At least basal acroscopic lobes of middle pinnae dentate. |
| 22 | Pinnae thin, copiously hairy on costae beneath; costal scales few. |
| 22' | Pinnae rigid; costae sparsely hairy beneath and bearing many small scales |
| 23 | Hairs on lower surface of costae unicellular 16. C. pectiniformis |
| 23' | Hairs on lower surface of costae to 1.5 mm long, septate |
| 24 | Pinnae c. 1.6 cm. wide; veins 7-8 pairs; hairs on lower surface of costae over 0.5 mm long |
| 24' | Pinnae c. 0.8 cm wide, veins 3-4 pairs; hairs on lower surface of costae c. 0.1 mm long |
| 25 | Lamina to 15 cm long; largest pinnae 3.0 x 0.8 cm |
| 25' | Lamina always much longer; pinnae in most cases to at least 5 x 1 cm. |
| 26 | Lower pinnae, at least 2 pairs, reduced; basal pinnae not wider than next above them. |
| 26' | Basal pinnae wider and not shorter than those next above them. |
| 27 | Six or more pairs lower pinnae gradually reduced; lowest 1.5-2 cm long; stipe commonly to 15 cm long |
| 27' | 2-4 pairs lower pinnae reduced, lowest larger; stipe 20-25 cm |
| 28 | Fertile pinnae to 4.5 x 1.2 cm; stipe-scales to 2.5 mm wide |
| 28' | Fertile pinnae to 8.5 x 1.7 cm, stipe-scales 1 mm wide |
| 29 | Basal acroscopic lobe of basal pinnae free. |
| 29' | Basal acroscopic lobe of basal pinnae not free. |
| 30 | Glands on lower surface usually confined to costules and veins; no hairs between veins on upper surface. |
| 30' | Glands present between veins on lower surface and hairs between veins on upper surface. |
| 31 | Lamina to 25 cm long; pinnae 12-15 pairs. |
| 31' | Lamina to 40 cm long; pinnae to 20 pairs |
| 32 | Basal pinnae to 9 x 2 cm; most pinna-lobes almost entire |
| 32' | Basal pinnae to 6 x 1.2 cm; most pinna-lobes dentate or crenate |
| 33 | Stipe-scales less than 1 mm wide above dilated base. |
| 33' | Stipe scales at least 1 mm wide above base. |
| 34 | Pinnae to 18 pairs; lower surface of rachis bearing capitate hairs only; many capitate hairs between veins on upper surface |
| 34' | Pinnae to 25 pairs; lower surface of pinna-rachis bearing acicular hairs; no hairs between veins on upper surface |
| 35 | Pinna-lobes, except basal one, entire; glands present between veins on lower surface |
| 35' | Pinna-lobes all distinctly dentate; no glands between veins on lower surface |
| 36 | Indusia lacking |
| 36' | Indusia present. |
| 37 | Several pairs of free pinnules on lower pinnae |
| 37' | At most basal lobes free. |
| 38 | Upper surface bearing hairs between veins. |
| 38' | Upper surface between veins normally glabrous. |
| 39 | Hairs on upper surface between veins acicular. |
| 39' | Hairs on upper surface between veins capitate |
| 40 | Stipe bearing copious hairs 1 mm long |
| 40' | Stipe bearing hairs 0.5 mm long in groove only |
| 41 | Lower surface of rachis bearing acicular hairs, costae usually also. |
| 41' | Lower surface of rachis and costae lacking (or almost lacking) acicular hairs. |
| 42 | Some hairs on upper surface of costae septate |
| 42' | Hairs on upper surface of costae unicellular. |
| 43 | Several pairs lower pinnae gradually reduced, longest 5.5 cm, lowest 1-2 cm |
| 43' | Lower pinnae not or little reduced. |
| 44 | Texture rigid; pinnae to 3 cm long; hairs on lower surface of rachis 0.5 mm long |
| 44' | Texture thin; pinnae to 6.5 cm long; hairs on lower surface of rachis 0.2 mm long |
| 45 | Short capitate hairs present on lower surface of costae and costules and on indusia |
| 45' | Capitate hairs lacking or rare on lower surface and indusia. |
| 46 | Sori supramedial; stipe-scales 8-10 mm long |
| 46' | Sori medial or inframedial; stipe-scales not over 5 mm long. |
| 47 | Sori mostly athyrioid; pinnae to 2.5 cm long |
| 47' | Sori mostly not athyrioid; pinnae longer. |
| 48 | Caudex erect. |
| 48' | Caudex slender, long-creeping |
| 49 | Pinnae thin; no tangled hairs at base of stipe. |
| 49' | Pinnae thick; tangled hairs often present at base of stipe |
| 50 | Veins 3-4 pairs; pinna-lobes entire except basal acroscopic ones. |
| 50' | Veins c. 6 pairs; pinna-lobes mostly crenate. |
| 51 | Pinnae caudate-acuminate |
| 51' | Pinnae short-acuminate |
