2 
7 - Leaf blade and sporophyll both ternateiy compound; veins not reticulate 
.* *. *... •••.•••••«•• . Botrychium 
7 - Leaf blade simple; sporophyll a simple spike or rarely dichotomously 
branched, veins reticulate.*.«. Qphiogl o spurn. 
S - Sporangia united into boat-shaped or circular structures 
(synangia) ; on short thick stalks or sessile, leaves 
triangular, with ’’stipules” (Marattiales). ..... .• ••» Harattia 
8 - Sporangia separate from one another, usually on slender stems 
(sometimes otherwise) ; leaves without ’’stipules” at the 
base (Filicales) . ••»•.».... ..... 9 
9 - Sterile leaves slender, wiry, non-leaf-like; sporangia not on margin, 
borne in short terminal spikes; on clayey banks at high altitudes 
(Schizaeaceae) . ...... ... Schizaea 
9 - Sterile leaves leaf-like; sporangia scattered or in sori on the edges 
or under surfaces of leaf-like fronds ....• ••• iO 
10 - Leaves pseudo-dichotomous, usually with a bud between the 
paired divisions, giving the appearance of indefinite growth; 
sori with no indusium, small, circular (Gleicheniaceae) .••* .• 11 
10 - Leaves simple, pinnately divided, or ternateiy divided ........ . 13 
11 - Fronds once-pinnate above the highest fork... ........ .• ••• i2 
11 - Fronds b ip innate above the last fork. ....••••••• .• * • Hicriop ter is_ 
12- Lower veins of the leaf segments branched more than twice.••• Dicranopteris 
12- Lower veins of the leaf segments branched twice ..*. Sticherus 
13 - Fronds climbing, pinnate with pinnae ternate, sporangia large, single 
on margins of midified pinnules (Schizaeaceae) ..• •• Lygodium 
13 - Fronds not climbing, pinnae rarely ternate, sporangia small, clustered 
or in lines or over the surface... ^ 
14 - Indusium valvate or tubular ( i.e , sorus or sori in a capsule or 
tubular-like covering).... 13 
14 - Indusium neither valvate nor tubular; indusium various or 
absent ......... 22 
15 - Indusium valvate, the outer valve formed by a teathery outgrowth 
from the margin of the leaf, dorsal upon the veins; tree ferns 
(Cyatheaceae) .......... • • • Cibotiurn. 
15 - Indusium tubular, not leathery; sori terminal on the veins.. 16 
