344 
KEYS TO THE FERNS OF BORNEO 
28. CYSTODIUM J. Smith. 
C. so rbi folium (Sm.) J. Sm. Saccoloma, Christ; 
Dicksonia, Sm. 
Sarawak. Dutch Borneo, British North Borneo 
(Kinabalu). 
Malaya. 
The nearest relative of this fern, sometimes united 
with it, but in my opinion distinct, is C. papuanutn 
(F. Muell.) ( Dicksonia papuana F. Muell., Descr. Pap. PI. 
4 (1876) 76.). 
Cystodium has the aspect of true Dicksonia, but an 
interrupted annulus. It is decidedly not at home in 
Saccoloma, which has the habit of Balantmm rather than 
of Dicksonia. 
29. NEPHROLEPIS Schott. 
a. Sorus continuous along the margin 
a*. Sori separate. 
b. Sori solitary on the apices of lobes 
b*. Sori not occupying the tips of lobes. 
c. Rhizome scandent 
c 1 . Rhizome not scandent. 
d. Indusium reniform with an open 
sinus. 
e. Indusium facing apex of pinna 
<?i. Indusium facing margin 
di. Indusium roundish, sinus usually 
closed. 
e. Surfaces bearing fine scales 
e*. Surfaces bearing simple hairs 
r2. Surfaces naked or nearly so 
d 2. Indusium attached by base, open 
at apex 
1. N. acutifolia. 
2. N. acuminata. 
3. N. radicans. 
4. N. cordifolia. 
5. N. exaltata. 
6. N. hirsutula. 
7. N. pilostila. 
8 . N. biserrata. 
9. N. marginalis. 
1. N. acutifolia (Desv.) Christ. 
Sarawak. 
Palseotropic. 
2. N. acuminata (Houtt.) Kuhn. 
Dutch Borneo, British North Borneo. 
Malaya, New Guinea. 
3. N. radicans (Burm.) Kuhn. 
Sarawak, Dutch Borneo. 
Malaya to India. 
