1 | Plants small (dwarfed) and/or fronds simple. |
1' | Plants not dwarfed. Fronds pinnate. |
2 | Bulbil ± terminal. Pinnae 16-30 |
2' | Bulbils subterminal (or absent). Pinnae less. |
3 | Veins irregularly anastomosing, usually with many ex- and recurrent free veins. Fronds entire or (bi)trifid |
3' | Veins regularly anastomosing, without free veins or with few ex- and recurrent free veins. Fronds entire. |
4 | Fronds coriaceous. |
4' | Fronds herbaceous (to subcoriaceous). |
5 | Areoles (except the costal one) all of about the same shape, decreasing in size towards the margin |
5' | Areoles of different size and shape, not decreasing in size towards the margin. |
6 | Fronds pinnate. Venation of terminal segment as in Fig. 31j, k |
6' | Fronds entire or if pinnate with a venation as in Fig. 31g or simpler. |
7 | Veins free. |
7' | Veins anastomosing. |
8 | Bulbil ± terminal on the lamina. Spines on the margin of the pinnae ± flattened at their bases. Base of pinnae symmetrical |
8' | Bulbil subterminal on the lamina. Spines on the margin not flattened at their bases. Base of pinnae symmetrical or asymmetrical. |
9 | Perispore smooth. Base of pinnae symmetrical, margin lobed 1/3-⅔(-¾) towards the costa |
9' | Perispore reticulate. Base of pinnae either symmetrical or asymmetrical; if symmetrical, margin of the pinnae entire or lobed to ⅓(-1/2) towards the costa |
10 | Fronds ± coriaceous. |
10' | Fronds herbaceous. |
11 | Terminal segment conform to the pinnae, though usually larger |
11' | Terminal segment triangular |
12 | Fronds drying reddish. Perispore undulate |
12' | Fronds drying greenish. Perispore undulate, cristate-undulate, or cristate. |
13 | Terminal segment conform to the pinnae or composed of 2 or 3 lobes. |
13' | Terminal segment triangular. |
14 | Venation pattern with many excurrent included free veins. |
14' | Venation pattern without or with only few excurrent (and recurrent) included free veins. |
15 | Perispore undulate. |
15' | Perispore cristate |
16 | Pinnae 2-10(-15) to a frond |
16' | Pinnae more than 15 to a leaf |
17 | Bulbil ± terminal. Small plant |
17' | Bulbil subterminal. |
18 | Terminal segment narrowly triangular. Perispore undulate |
18' | Terminal segment triangular. Perispore cristate or cristate-undulate. |
19 | Venation pattern irregular. See Fig. 27i |
19' | Venation pattern regular. |
20 | Base of pinnae narrow-acute or -cuneate. Pinnae 7.5-12 by 1-1¾ cm |
20' | Base of pinnae wider. Pinnae usually larger |