KEYS TO THE FERNS OF BORNEO 
365 
35. MESOCHL/ENA R. Brown. 
a. Pinnae lobed 1/4 of the way to the costa 
a 1. Pinnae lobed half-way to the costa. 
1. M. larutensis. 
b. Lower pinnae broadly triangular, imbri- 
2. M. Toppingii. 
3. M. polycarpa. 
cate 
bi. Lower pinnae less developed 
1. M. larutensis (Bedd.) v. A. v. R. 
Dutch Borneo, Sarawak. 
Perak. 
Van Alderwerelt distinguishes the Dutch Borneo 
form, with the lamina naked above, as var. borneensis. 
2. M. Toppingii Copel. n. sp. 
North Borneo. 
Local. 
3. M. polycarpa (Bl.) Bedd. 
Sarawak. 
Malaya to Polynesia. 
36. POLYSTICHUM Roth. 
a. Rachis not scaly. 
b. Frond tripinnate 
b 1. Frond quadripinnate 
1. P. arista turn. 
2. P. carvifolium. 
3. P. aculeatum. 
fli. Rachis scaly 
1. P. aristatuM (Forst.) Presl. 
Sarawak, Kinabalu. 
Malaya to Natal, India, Japan and Polynesia. 
2. P. carvi folium (Kze.) C. Chr. 
Kinabalu. 
Range of the preceding, and Australia. 
The best distinction between the two preceding 
species is that the former has a creeping rhizome, the 
latter a stout, suberect one. I have seen no rhizomes 
from Borneo, and suspect that fronds from Sarawak as 
well as Kinabalu represent P. carvifolium . The Kinabalu 
specimens are identified by the dark, coarse palese at the 
base of the stipe. 
