560 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Lamina deeply pinnatifid or sub- 
pinnatisect, the segments 
fully adnate. 
Fronds 3.5 to 14 em. long; lam- 
ina 2 to 5.5 cm. long, coria- 
ceous. 
Rhizomes wide-creeping; 
rhizome scales nearly 
entire to obtusely sub- 
denticulate............. 
Rhizomes creeping; rhizome 
scales deeply and irregu- 
larly denticulate. 
Scales of rhizome narrowly 
linear-deltoid, almost 
acicular............... 
Scales of rhizome attenu- 
ate or long-acuminate 
from a relatively broad 
deltoid-ovate base; 
plants smaller. ....... 
Fronds 15 to 30 cm. long; lam- 
ina 10 to 18 cm. long, mem- 
brano-herbaceous.......... 
Lamina fully pinnate, the seg- 
ments sessile or subsessile, 
often deeply pinnatifid...... 
Rhizome scales roundish-ovate _ to 
broadly oblong, sharply and nar- 
rowly fuscous-carinate, the broad 
pale borders (except in no. 16) 
repand to complicate-crispate. 
Fronds subdimorphous, the sterile 
ones short-stipitate, with a 
very broad lamina; fertile 
fronds long-stipitate, the lam- 
ina linear-oblong............ 
Fronds uniform. 
Scales of the lamina minute, 
very few, inconspicuous. - . 
Scales of the lamina large or, if 
small, at least very numer- 
ous. 
Segments oblique, conspicu- 
ously crenate..........-- 
Segments divergent, suben- 
tire or remotely and 
minutely notched. 
Scales of the lamina rela- 
tively large, conspicu- 
ous, castaneous, plane, 
broadly ovate or del- 
toid-ovate, long-acumi- 
nate, the margins bi- 
dentate. ...-.......-. 
- ll. P. bryopodum. 
12. P. pyenocarpum. 
13. P. mollendense. 
14. P. rusbyt. 
15. P. murorum. 
16. P. lewcosticton. 
17. P. plebejum. 
18. P. tweedianum. 
19. P. guttatum. 
