| 1 | Lamina simply pinnate and with a conform terminal pinna (Fig. 14). |
| 1' | Lamina more strongly dissected, or, if simply pinnate, the upper pinnae reduced and confluent into a pinnatifid leaf-apex, or at least the terminal division strongly lobed at its base. |
| 2 | Sori submarginal, most often binerval; petiole and rachis abaxially sharply bi-angular; scales to 5 mm long |
| 2' | Sori intramarginal, almost always uninerval; rachis abaxially sharply bi-angular or sulcate, basally dark and pale-margined; scales to 2.5 mm long |
| 3 | Lamina simply pinnate, or, if more dissected, the primary rachis abaxially sharply carinate; at least a considerable Upper portion of the petiole abaxially bi-angular. |
| 3' | Lamina at least pinnate + pinnatifid; primary rachis abaxially terete or bi-angular, or, if obtusely carinate, the petiole abaxially not (or only at the apex) sharply bi-angular. |
| 4 | Petiole, at least in the upper part, and rachis dark, pale-angled; lamina pinnate + pinnatifid or bipinnate. |
| 4' | Petiole pale, or, if occasionally darker, the rachis not also dark and pale-angled; or lamina simply pinnate. |
| 5 | Larger pinnae of full-grown plants 20-25 mm wide at the widest point; texture subcoriaceous; margin often reflexed in dry leaves; lobes of larger pinnae sinuate, the sori not on lobes |
| 5' | Larger pinnae of full-grown plants 10-12 mm wide at the widest point; texture herbaceous; margin not reflexed; lobes of larger pinnatifid or basally subpinnate pinnae lobed, each sorus on a lobe: smaller forms of |
| 6 | Lamina to 12 cm long; petiole slender, less than 1 mm ø |
| 6' | Lamina larger; petiole stouter. |
| 7 | Petiole abaxially obtusely bi-angular, dark and dull, ± pale-angled; rachis abaxially mostly narrowed-rounded; sori submarginal, on saw-teeth; lamina simply pinnate. |
| 7' | Petiole abaxially sharply bi-angular at least near the apex, nearly always pale; rachis abaxially carinate or bi-angular; sori intramarginal; lamina variously dissected. |
| 8 | Lamina pinnate + pinnatifid or more incised1 |
| 8' | Lamina simply pinnate or in large leaves the basal pinnae with very few basal lobes |
| 9 | Primary rachis atropurpureous; secondary rachises (except sometimes the basal ones) abruptly pale; pinnae pinnatifid, with crenate segments, only the basal pinnae occasionally with some pinnatifid basiscopic pinnules; most sori with their greatest extension at right angles to their vein. |
| 9' | Primary rachis at least at the base dark; secondary rachises pale; pinnae pinnate + pinnatifid or subbipinnate; sori with their greatest extension in the Prolongation of the vein |
| 9'' | Primary rachis pale, or, if dark, the secondary rachises not abruptly pale; lamina often more incised. |
| 10 | All axes, except the primary, green-margined to base or almost so, i.e., lamina only once fully pinnate, then pinnatifid; secondary axes abaxially rounded |
| 10' | Lamina mostly fully bipinnate; secondary rachises, if marginate, abaxially carinate. |
| 11 | Secondary rachises abaxially black, with two pale lateral or one pale median ridge; lamina bipinnate or almost so, with superficially crenato-lobate pinnules; pinnae not enlarged at the base |
| 11' | Secondary rachises abaxially various, but not black with pale ridges; lamina often bipinnate + pinnatifid. |
| 12 | Primary rachis and indusia black; ultimate lobes abaxially with very broad and prominent veins occupying of their width (Fig. 9) |
| 12' | Primary rachis and indusia pale to dark brown; ultimate lobes with immersed, if slightly prominent, relatively much narrower veins. |
| 13 | Indusia about twice as broad as long, 0.3 mm long; margin bordering the apical sorus of the segment usually denticulate; texture herbaceous |
| 13' | Indusia longer, or, if only 1/3 mm long, ± isodiametric or longer than broad2; margin bordering the apical sorus entire, or no apical sorus; texture firmer. |
| 14 | Larger segments pinnatifid, each lobe with a sorus overtopped by part of the lobe (Fig. 6). |
| 14' | Larger segments (except for the basal pinnae) crenate, each lobe with a terminal or subterminal sorus. |
| 15 | Secondary rachises abaxially terete in a considerable basal portion; basiscopic pinnules of basal pinnae usually enlarged and more dissected than the others (Fig. 10) |
| 15' | At least the larger secondary rachises abaxially carinate; basiscopic pinnules of basal pinnae rarely enlarged and more dissected (Fig. 11) |
