| 1 | Ultimate branches (branches on each side of an ultimate dormant apex) bipinnatifid. |
| 1' | Ultimate branches simply pinnatifid. |
| 2 | Segments of the lamina not much longer than wide; one sorus on each segment. |
| 2' | Segments of the lamina elongate, the costule bearing several forked veins, each of which may bear a sorus on its acroscopic branch. |
| 3 | Fully developed pinnule-lobes not deeply concave beneath (the edges only slightly revolute). Tissues adjacent to costa not swollen. Sporangia when young in a circular depression in the lamina. |
| 3' | Fully developed pinnule-lobes deeply concave beneath, the distal edges strongly revolute. Tissue adjacent to the costa more or less swollen. Sporangia not in a depression in the lamina. |
| 4 | Edge of depression occupied by sorus distinctly raised. Small scales on lower surface of lamina. |
| 4' | Edges of depression occupied by sorus not raised. No small scales on lower surface of lamina. |
| 5 | Costae persistently scaly; tissue adjacent to the costa slightly swollen. Sporangia often 3. |
| 5' | Costae of fully developed fronds usually quite glabrous; tissue adjacent to the costa much swollen. Sporangia 2 |
| 6 | Scales on dormant apex of rachis entire, to 10 by 3 mm. Segments of lamina at c. 45° to costae. |
| 6' | Scales on dormant apex of rachis fringed with hairs or setae, or with a broad translucent margin. Segments of lamina almost at right angles to costae. |
| 7 | Scales on dormant apex of rachis 1 mm wide or more, edges fringed with spreading hairs to 0.5 mm long, or with translucent edge bearing fine short hairs. |
| 7' | Scales on dormant apex of rachis narrower, their edges bearing short stiff oblique setae. |
| 8 | Rachis-branches persistently quite covered with scales, or with a mixture of scales and hairs, on lower surface. |
| 8' | Rachis-branches not persistently quite covered with scales nor with a feit of stellate hairs on the lower surface. |
| 9 | Rachis-branches covered almost entirely with thin brown scales 4-5 mm long and nearly 1 mm wide, stellate hairs few |
| 9' | Rachis-branches covered with a dense feit of stellate hairs, and also with i abundant scales. |
| 10 | Pinnules commonly 12-16 by 2-2½ cm. Upper surface of the lamina not swollen between the veins. Stipular leaflets present |
| 10' | Pinnules commonly 6-9 by 0.9-1.3 cm. Upper surface of the lamina much swollen between the veins. No stipular leaflets |
| 11 | Very few persistent scales on the lower surface of rachises and costae. Pinnules to 22 by 3.5 cm. |
| 11' | Many persistent dark scales on rachises and costae. Pinnules to 12 by 2 cm |
| 12 | Segments of the lamina near base of each pinnule constricted at the base (i.e. widening just a little above the constriction), joined together by a very narrow wing of even width along the costa. |
| 12' | Segments of lamina near base of each pinnule not thus constricted (or not more than one segment on the largest pinnules). |
| 13 | Many such segments (20 or more pairs) on each pinnule. |
| 13' | Few (at most 7-8) such segments on each pinnule. |
| 14 | Lamina rigid; segments of lamina 2½ mm wide; scales of dormant apex uniformly dark brown |
| 14' | Lamina thin; segments of lamina 3½ mm wide; scales of dormant apex pale with dark edges. |
| 15 | Pinna-rachises more or less persistently scaly; costules 3½-4½ mm apart. |
| 15' | Pinna-rachises sparsely scaly, soon glabrous; costules 5½-7 mm apart. |
| 16 | Stipular leaflets having lobes similar to pinnule-segments, not narrow and acuminate. Scales on rachis-apex not dark-fringed |
| 16' | Stipular leaflets having very narrow acuminate lobes quite different from normal segments of pinnules. Scales on rachis-apex dark-fringed. |
| 17 | Distal half of each rachis-branch strongly zig-zag, the pinnules deflexed so that each is in line with the part of the rachis beyond it |
| 17' | Distal half of each rachis-branch not thus zig-zag. |
| 18 | Pinnules c. 10 by 2 cm |
| 18' | Pinnules commonly 20 by 3-4 cm. |
| 19 | Dark rigid stellate hairs abundantly persistent on the lower surface of veins and lamina. |
| 19' | Stellate hairs light brown, not abundant nor persistent on the lower surface of veins and lamina |
| 20 | Stipule-like leaflets, different from ordinary segments of the lamina, present at the branchings of the main rachis (on fronds of mature size). |
| 20' | Stipule-like leaflets absent (sometimes present in G. loheri var. major). |
| 21 | Segments of lamina at right angles to the costa, or more or less deflexed. Lower surface not con- spicuously glaucous. |
| 21' | Segments of lamina distinctly oblique-ascending. Lower surfaces distinctly glaucous. |
| 22 | Segments of lamina deflexed (lower ones much so), thick, with edges much revolute when dry. Main rachis-branches once or twice forked |
| 22' | Segments of lamina not or little deflexed. Main rachis-branches often more than twice forked. |
| 23 | Forkings of rachis-branches equal or nearly so, not alternately unequal with larger branches at successive forks forming almost a straight line. |
| 23' | Forkings of rachis-branches unequal, the larger branch at successive forks alternately to left and right, axes of these larger branches in almost straight line. |
| 24 | Scales on costules very abundant, spreading so as almost to cover the lower surface of the lamina. Veins on lower surface strongly raised |
| 24' | Scales on costules not persistently covering the lower surface of the lamina. Veins not strongly raised |
| 25 | Primary branch-systems 5 times forked on large fronds, branches of all Orders except the first leafy; no stellate hairs on the lower surface of veins |
| 25' | Primary branch-systems twice forked; stellate hairs (or at least their bases) persistent on the lower surface of veins |
| 26 | Margins of segments of lamina not distinctly toothed. |
| 26' | Margins of the segments of the lamina distinctly toothed, at least towards the apex. |
| 27 | Only the ultimate branches fully leafy (penultimate without lamina or with some scattered segments). |
| 27' | At least the penultimate branches fully leafy, lower ones sometimes also. |
| 28 | Ultimate branches to 20 cm long |
| 28' | Ultimate branches 30-40 cm long. |
| 29 | Segments of the lamina to 25 mm long, costules 5½-6 mm apart. Primary rachis-branches usually 3 times forked |
| 29' | Segments of lamina to 17 mm long, costules 4 mm apart. Primary rachis-branches usually twice forked |
| 30 | Lamina-segments rarely more than twice as long as the distance between bases of adjacent costules. |
| 30' | Lamina-segments much more than twice as long as the distance between adjacent costules. |
| 31 | Segments 8-12 mm long, costules 4-5 mm apart. Rachis-branches of 1st and 2nd Orders 3-4 cm long. Scales on the main rachis-apex brown, more than 1 mm wide at base; scales on the costae rusty brown |
| 31' | Segments 3-6 mm long, costules 3 mm apart. Rachis-branches of 1st and 2nd Orders 1-2 cm long. Scales on the main rachis-apex very dark, narrower; scales on the costae dark at base, paler distally |
| 32 | Scales on the costae only a few cells wide at the base, about half their length consisting of a hair, these hairs crisped and entangled |
| 32' | Scales on the costae with short hair-points, their bases wider and their apices not entangled. |
| 33 | Costules at 60°-70° to costae |
| 33' | Costules at almost a right angle to the costae. |
| 34 | Ultimate branches 25-45 cm long, 3-4½ cm wide; costules on ultimate branches 4-5 mm apart |
| 34' | Ultimate branches smaller, costules on ultimate branches 3-4 mm apart. |
| 35 | Margins toothed almost to base of segments. Costules at c. 45° to costae. |
| 35' | Margins toothed only near apex of segments. Costules at wider angle to costae. |
