The Philippine Journal of Science, C. Botany. 
Vol. XI, No. 4, August, 1916. 
HAWAIIAN FERNS COLLECTED BY J. F. ROCK 
By Edwin Bingham Copeland 
(From the College of Agriculture, University of the Philippines, Los 
Banos, P. I.) 
Through the courtesy of Mr. J. F. Rock of the College of 
Hawaii, I have recently had an opportunity to study the ferns of 
the College of Hawaii herbarium, and have found among them 
the following apparently undescribed species. In some groups, 
especially Polypodium, this collection is notably richer than 
Faurie’s, 1 while in other, such as Asplenium, it is not so com- 
plete. All the specimens here described were collected by Mr. 
Rock. 
ATHYRIUM PSEUDOARBOREUM sp. nov. 
Asplenium arboreum Hilleb. non Willd. quid Athyrium arboreum 
Milde. 
A. arboreo (Willd.) Milde similis, sed paleis brunneis latio- 
ribus prope baseos stipitum, soris longis marginem fere attingen- 
tibus, et indusiis latis versus margines suas albidis distinctum, 
et propter eas indicationes versimiliter phylogenetice diversum. 
Lanai, Mahana Valley, in shady, damp places, altitude 770 meters. Rock 
8081. 
There is no question that this is the Asplenium arboreum of Hillebrand, 
page 609, who modified the description, as regards the sori, to fit this 
fern. But much as the two are superficially alike, Asplenium arboreum is 
a clear-cut member of an American group of species, while 1 Athyrium 
pseudo arboreum represents the Oriental group of Athyrium japonicum. 
Athyrium kaalaanum Copel. 2 is also one of this group, but I do not 
believe it is a juvenile or reduced form of Athyrium pseudoarboreum; it 
has fleshy stipes, a long apex, obtuse pinnae, and short sori. Except for 
acuminate pinnae and the absence of a gemma, Athyrium pseudoarboreum 
fits Presl’s diagnosis of Diplazium sandwichense, and I would be tempted 
to use this name if Asplenium sandwichianum were not already in use. 
SADLER 1 A RIGIDA sp. nov. 
Caudice ignoto; stipitibus ca. 15 cm longis, validis, ubique 
densissime paleatis ; paleis linearibus, rigidulis, crinitis, rufocas- 
taneis costa spuria castanea, infimis 3 cm longis pallidioribus, 
sursum usque ad rachides secondarias etenim ad costulas decres- 
centibus, ibidem costa carentibus; fronde elliptica vel ovata, 
ca. 33 cm longa, 20-25 cm lata, abrupte acuminata, rhachi dense 
' Philip. Journ. Sci. 9 (1914) Bot. 435. 
2 Op. cit. 438. 
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