392 
KEYS TO THE FERNS OF BORNEO 
Section 3. Fronds deeply pinnatifid or pin¬ 
nate ; sori more than one on each segment. 
a. Surfaces glandular-hairy 
a 1 . Surfaces hairy, not glandular. 
b. Sori superficial. 
c. Membranaceous, with pale hairs 
c 1 . Texture firmer and hairs dark 
b 1. Sori slightly immersed 
b 2 . Sori much immersed 
ai. Surfaces finely scaly 
43. Lamina glabrous or nearly so. 
b. Rachis not ebeneous. 
c. Pinnatifid to a broad wing 
c 1. Cut within 1 mm of rachis. 
d. Lower pinnae or segments not or but 
slightly reduced. 
e. Coriaceous 
<?i. Very thin 
d 1 . Fronds gradually narrowed below. 
e. Sori superficial. 
/. Segments entire 
Ji. Segments wavy 
* 
e*. Sori slightly immersed 
ez. Sori decidedly immersed. 
/. Sori elongate and oblique 
p. Sori roundish or not oblique. 
g. Frond about 2 cm. wide 
gi. Frond 7-8 cm. wide 
bi. Rachis black or nearly so. 
c. Sori almost superficial. 
d. Segments linear 
di. Segments broad, often deltoid 
ci. Sori distinctly immersed. 
d. Sorus cavities not ciliate. 
c. Segments about 1 mm. wide 
ei. Segments about 2 mm. wide 
di. Sorus cavities ciliate 
Section 4. Fronds at least bipinnatifid, with 
narrow segments. 
a. Segments of pinnae entire 
ai. Segments of pinnae coarsely toothed 
29. P. Merrittii. 
30. P. minutum. 
31. P. mollicomum. 
32. P. subrepandulum. 
33. P. cryptosorum. 
34. P. malaccanum. 
39. P. Burbidgei. 
49. P. cesatianum . 
50. P. papillosum. 
35. P. nutans. 
36. P. subfalcatum. 
37. P. repandulum 
38. P. obliquatum. 
40. P. barathrophyllum. 
41. P. celebicum. 
42. P. pcdiculatum. 
43. P. denticulatum 
44. P. Moultoni. 
45. P. blechnoides. 
46. P. decorum. 
47. P. taxodioides. 
48. P. millefolium. 
