| 1 | Pinnules 30-40 mm long; lower pinnae gradually reduced. |
| 1' | Pinnules commonly at least 70 mm long, in most cases much longer. |
| 2 | Tertiary leaflets on stalks almost 1 mm long. Pinnae to 25 cm long. Bullate scales present on costules. |
| 2' | Tertiary leaflets almost sessile. Pinnae to 45 cm long. No bullate scales on costules. |
| 3 | Lower pinnae gradually reduced, lowest 11 cm long near base of stipe. |
| 3' | Lower pinnae not thus reduced (sometimes 1-2 pairs of isolated small pinnae at base of stipe). |
| 4 | Bullate scales present on costae and costules. |
| 4' | Bullate scales lacking. |
| 5 | Pinnules to 110 by 22 mm. Soral scales small, not covering sorus at maturity. |
| 5' | Pinnules to about 65 by 16 mm. Soral scales broad, covering sorus at maturity. |
| 6 | Veins and lower surface of lamina bearing finely fringed interlacing scales which cover lower surface of leaflets |
| 6' | Veins bearing at most small separate scales on lower surface. |
| 7 | Scales absent from lower surface of veins |
| 7' | Scales present on lower surface of veins, not long-fringed nor covering lower surface of leaflets. |
| 8 | Spines on stipe scattered, 1-3 mm long; soral scales many, covering sorus to maturity. |
| 8' | Spines on stipe copious, to 5 mm long; soral scales not covering sorus at maturity. |
