43 



sporangiuni is surrounded by a broad, transverse, equatorial 

 annulus, and opens \ertically.* The spores arc ovoid or tet- 

 rahedral, williout chloroijlull and w i(h a sin.u,K' dorsal line. 



1. Gleichenia Hawaiiexsis Hook. 

 Dicranopteris Hawaiiensis (Hook.) Robins.; Mertensia Hawaiien- 



sis Brack. 



Petiole rough, compressed, and margined with two lines of 

 small scales. The leafy portion is 3 or 4 times dichotomous at 

 somewhat acute angles. All of the divisions are pectinately 

 pinnatifid down to the rachis. There is a bud in each fork, 

 covered with small (iK^-2 lines), falcate, acute, dark, ciliate 

 scales. Ultimate divisions of the leaf-blade are linear-lanceolate, 

 6-12 inches long; their segments are linear, rather acute, sub- 

 coriaceous, dark-green, >^-i>2 inches long, their under side, and 

 more so the rachis, chaffy with laciniate ferruginous scalelets. 

 The veins are vertical, with 2 or 3 branches. The sori are on 

 raised punctiform receptacles, copious and close, with 3-6 spor- 

 angia in each sorus; often the sporangia are irregularly scattered. 

 Annulus indistinct ; spores compressed. 



Th[s species occurs on all the islands, at elevations of 3,000- 

 6,000 ft., but is rare. Typical stations are: Halemanu, Kauai; 

 Ka-ala and Kona-hua-nui, Oahu; Pele-kunu, Molokai; Eeke, 

 West Maui; and Mauna Kea, Hawaii. It is distinctly a plant 

 of the montane rain-forests, and does not descend to the lower 

 levels or give any evidence of xerophytic tendencies. It is 

 endemic, but according to Hillebrand is closely related to G. 

 flagellaria Spring., which extends from Madagascar and Malaysia 

 up through southern Polynesia. It is notably shade-tolerant, 

 and does not form large thickets, but grows in isolated clumps 

 here and there in the forest. Its distinctive feature is that all or 

 most of the petiole branches are foliose. 



2. Gleichenia longissima Blume 

 Dicranopteris glauca (Thunb.) Underw. ; Gleichenia glauca Hook. ; 



Mertensia glauca Brack. ; Mertensia pinnata Kze. 



*F. O. Bower, Studies in the Morphology of Spore producing Members. I\', 

 The Leptosporangiate Ferns, Phil. Trans. Roy. Soc, Series B, Vol. 192: 29-138. 

 1899. 



