THE FBEN WOULD OF AUSTRALIA. 
25 
IX. — Platyzoma, R. Br. 
. Rhizome horizontal, upon which the fronds are densely tufted, 
fronds pinnate, pinn^ small numerous. Soriof two to four spore- 
cases terminating simple veinlets proceeding from the midrib, the 
soriferous end free and incurved between the frond and an inner 
membrane. Spore-cases globular, very deciduous, bursting irregu- 
larly, the inner membrane of the pinna irregularly torn and 
disappearing. Name from the broad band of spore-case. 
P. micropliyllum, R. Br. Braid fern. Rhizome densely 
covered with long brown setaceous scales, fronds narrow, linear, 
rigid, six to twenty -four inches high. The rhachis smooth and glossy. 
Pinnae exceedingly numerous, about a line long and broad ; the 
revolute margins almost closed over tbe midrib so as to give them a 
globular, or ovoid, bullate form, glabrous outside, powdery inside, 
especially on the midrib. Soriferous veins two or three on each side 
of the midrib. Found in several parts of North Australia and 
tropical Queensland, where on sandy hillocks it is said often to 
form a dense sward with its close, rigidly erect, fronds. 
X. — Gleichenia, Sm. 
Fronds from a creeping rhizome erect or scrambling, the main 
rhachis dichotomous, with numerous entire or pinnatifid pinnules 
distichous along the ultimate branches and often also below the last 
forks. . Sori without indusium of few (two to twelve) spore- cases 
attached to one branch of. forked veinlets, either superficial or 
slightly embedded in the substance of the frond. Spore-cases 
surrounded by a transverse ring and opening vertically in 2 valves. 
Name in honor of K, W. F. von Gleichen, a German author on 
microscopic plants. 
G. circinata, Swartz. Parasol Fern. Fronds sometimes short, 
but often repeatedly dichotomous and scrambling to the height of 
many feet, the main rhachis glabrous or shortly scalj-hirsute. 
Pinnules numerous along the ultimate branches, one to two inches 
long, pinnately divided into numerous ovate or almost orbicular 
segments, one to two lines diameter adnate by the broad base, 
often whitish underneath, flat on the margin more or less recurved 
or revolute. Sori of two to four, spore-cases superficial or half 
immersed in a slight cavity near the upper base or angle of the 
segments. This is the most widely spread of all the Australian 
species, being found in all the colonies. The form G. microphylla 
R. Br. has a more hairy rhachis and is wanting in the whitish 
covering to the under side of the segments. This form belongs to 
the southern colonies. 
Gr. dicarpa, R- Br. Fronds like the small form of the last, with 
the rhachis glabrous or scaly-hispid, but the segments smaller 
almost globular and bullate, the revolute margins abnost closed 
over to the rhachis, thus becoming saccata (pouck-like), sori of two 
