| 1 | Juvenile (and more accessible) leaves not at all acuminate, adult leaves at least 6 cm long or else glaucous on the underside. |
| 1' | Juvenile leaves distinctly acuminate. Adult leaves less than 6 cm long and not glaucous on the underside. |
| 2 | Leaves not glaucous on the underside, at least 6 cm long. Pollen cones at least 4 cm long. Microsporophylls slightly acute and nearly as long as wide or large (over 5 mm long). |
| 2' | Leaves glaucous on the underside, no more than 6 cm long. Pollen cones less than 4 cm long. Microsporophylls blunt (much wider than long), less than 2 mm long. |
| 3 | Pollen cone at least 2 cm in diameter. Microsporophyll c. 6 mm wide, over 5 mm long, and blunt, resin canals in the leaves paired |
| 3' | Pollen cone more than 14 mm in diameter. Microsporophyll no more than 2.5 mm wide, 2 mm long, and slightly acute, resin canals in the leaves solitary. |
| 4 | Adult leaves never broadly rounded at the apex. Pollen cones 12-14 mm in diameter. Apex of microsporophyll at least 2 mm long and wide. Seed bract at least 42 mm wide and 32 mm high with more or less straight margins and the apex bluntly ridged |
| 4' | Adult leaves acute to broadly rounded at the apex. Pollen cones 9-12 mm in diameter. Apex of microsporophyll less than 2 mm wide and 1.5 mm long. Seed bract less than 42 mm wide and 32 mm high with more or less rounded margins and the apex sharply rigid |
| 5 | Adult leaves lens-shaped, 5-7 cm long. Pollen cones 3-4 cm by 9-10 mm. Microsporophyll 2-2.5 mm wide. Seed cone c. 6 cm in diameter, spherical |
| 5' | Adult leaves orbicular, blunt, 2.4-4 cm long. Pollen cones 8-14 by 4-6 mm. Microsporophyll 1.2-1.5 mm wide. Seed cone c. 4.5 cm in diameter, elongated |
| 6 | Adult leaves not acuminate. Microsporophyll helmet-shaped, the stalk attached near the centre of the apical part, at least 2 mm wide. Apex of the seed cone bract bluntly ridged. |
| 6' | Adult leaves acuminate or small and blunt. Microsporophyll shingle-shaped, the stalk attached below the centre of the apical part, 1.6-1.8 mm wide. Apex of the seed cone bract sharply ridged |
| 7 | Seed sharply angled opposite the wing. Mature pollen cone mostly at least 3.5 cm long by 10 mm in diameter. Seed cone bract 2.8-3.2 cm high. Adult leaves at least 4.5 cm |
| 7' | Seed bluntly rounded opposite the wing. Mature pollen cone 2-3.5 cm long by 7-10 mm in diameter. Seed cone bract 2.6-2.9 cm high. Adult leaves 3-4 cm long |
