A REVISION OF THE PHILIPPINE SPECIES OF ATHYRIUM 
By Edwin Bingham Copelaxd. 
{From the Bureau of Education, Manila, P. I.) 
4 
On the basis of the most thorough anatomical study the group has 
received, Milde ^ many years ago declared the distinctness of Athijrium 
from Asplenium, the close affinity of the former to Dryopteris, and the 
impropriety of the generic separation of Athyrium and Diplaziu7n. 
Diels in I^atiirlichen Pflanzenfamilien, and Christensen, in his Index 
Pilicum, have agreed Avith Milde in limiting Asphniutn, but no one 
seems to have followed him in merging both Diplazium and Anisogonimn 
in Athyrium. In work on the Philippine ferns it has become perfectly 
evident that each of these two genera, AiJiynum and DlpJazlum, as 
usually construed^ contains some members with herbaceous or subfleshy 
fronds, tawny or brown pale^, and exclusively fibrous roots, and others 
with characteristic, comparatively harsh fronds, almost black, harsli 
r 
palese, and stout black roots; and that each of these groups is more 
nearly related to the corresponding group in the other "genus" than to 
the other group of its own "genus." In other words, Athyrium being 
obviously the more primitive, Diplazium has had a double or plural 
origin in it.~ 
Athyrium silvaticum, (Bl.) Milde is closely related to the dominant 
group in Diplazium, in spite of the form of its sori. Diplazium japon- 
icum (Thunb.) and its relatives on the other liand arc intimately related 
to Athyrium in the usual sense, more so than to the main Diplazium 
group; one of the so-called Diplazia in this group is A, grammitoides 
(Presl), which Milde recognized as Euuthyrium. 
So long as intimate affinity and the difficulty of definition were the 
only grounds offered for combining these two genera, there was some 
opportunity for play of judgment, and for the continued maintainance 
of Diplazium as a valid genus. But once it is recognized that Diplazium 
has had a plural origin in Athyrium, I can imagine no sufficient ground 
for continuing to treat the former as of generic rank. The line between 
^Bas Genus Atliyriwm. Bot. Zeii. 24 (1806) 373-376. Uel>er Athyrium, AspTo- 
nium una Verwandte. Bot. Zcit, 28 (1870) 321), 345, 370. 
2 Comparative Ecology of San Ramon Polypodiaceae, ThiJi Journal 2 (1907) 
Bot. 6S. Pteridophyta Hak-onoiisia, iliidoin, pp. 127, 128. 
74379 2 285 
