ROBINSON: PTERIDOPHYTA OF THE HAWAIIAN IsLANDs 239 
thickets upon the mountain sides and sometimes in the valleys 
also. The attachment of the roots to the thin soil is very insecure 
and the man or beast that ventures to step upon the seemingly 
solid mass, where it has overgrown the trail in the mountains, 
may feel it give way, allowing him to slip far down the steep 
slope. Dicranopteris is known locally as stag-horn fern and is a 
pest in the cattle-raising districts, as stock refuse to graze upon it. 
DICRANOPTERIS Bernh. Neues Jour. Bot. Schrad. 1: 38. 
1806 
Rootstock creeping, much branching, 0.5-1 cm. in diameter; 
leafstalk 1-2 m. high, not articulated to the rootstock; rachis of 
indeterminate growth, bearing opposite lateral branches in acrop- 
etal succession, these simple or repeatedly forked; included 
buds sometimes developing axes similar to the primary; ultimate 
divisions pectinate, pinnate, or bipinnate; veins free; sori dorsal 
upon the veins, non-indusiate; sporangia sessile; annulus obliquely 
transverse, the dehiscence vertical. 
Type species: Polypodium pectinatum Thunb: 
Ultimate divisions bipinnate, the leafstalk not forked. 
innules sessile, the lower segments lobed and overlapping the 
rachis; leafstalk noticeably scaly. D. glauca. 
Pinnules stalked, the lower segments entire; leafstalk with few 
D. glabra. 
Ultimate divisions a pectinate, in pairs; the leafstalk once or 
several tim rked 
A pair of onalg diet d, equal or unequal pinnae borne 
at all except the ultimate forkings of the leafstalk; veins 
2-5-forked; segments mostly emarginate, connected by 
wing along rachis; sori 5—12-sporangiate 
Segments densely tomentose when young, somewhat less so 
with age; texture rigid; emarginate character of pinnules 
constant; sori mostly 8-sporangiate or less. D. emarginata. 
Segments glabrous or near tly so; texture chartaceous; 
eMarginate character of pinnules not constant; sori 
usually 12-sporangiate D. linearis. 
Ty pinnae wanting; segments not emarginate, nearly or 
uite free; rachis scaly; veins mostly once forked; sori 2-5- 
Sporangiate, D. owhyhensis. 
Dickanopreris Ghauca (Thunb.) Underw. Bull. Torrey Club 34: 
. 249. 1907 
sain glaucum Thunb.; Houtt. Nat. Hist. 14:177. 1783. 
“rensia glauca Sw. Sv. Vet.-Akad. Handl. Il. 2§:177. 1804. 
