24 
THE FERN WORLD OF AUSTRALIA. 
VII. — Marattia, Sm. 
Rhizome large globose, formed of the thick squamse-form bases 
of fronds. Fronds large bi-tri-pinnate, the stipes with adnate 
auricules at base. Spore-cases completly united in two rows, in oblong 
boat-shaped sori placed side by side in a continuous row close to 
the edge of the pinnules or between the mid-rib and margin, the 
spore-cases opening inwards in longitudinal slits without any other 
external mark to distinguish them, the sorus aj)pearing divided into 
so many cells in two rows. Name in honor of J. F. Maratti, of 
Tuscany, a writer upon Ferns. 
M. fraxinea, Sm. Potatoe Fern. Pinnules oblong, lanceolate, 
acuminate, four to six inches long, half-inch to one and half broad^ 
veins numerous, parallel simple or forked, points of barren pinnules 
often sharply serrated. Boat-shaped sori rather above a line long, 
oblique and close together in a continuous row close to the margin, 
the vein on which they rest sometimes shghtly expanded and fringed 
but scarcely so in the Australian form ; upper surface of the sorus 
concave, the slits and cells indicating the number of united spore 
cases five to eight pairs in each sorus. In tropical Queensland this 
fern is often very abundant on the wet banks of mountain creeks 
seeming to delight in rich soil and dense scrub, also found on Lord 
Howe's Island, N. S. Wales, but this form is said to have smaller 
pinnules and longer sori of fifteen to twenty pair of spore-cases. 
Tr iBE III. — OsMUNDiE. Frouds circinate in vernation, divided 
or compound. Spore-cases globular or nearly so, without any or 
with an imperfect or transverse ring, opening in two valves or 
irregularly, few, sometimes solitary, rarely many and clustered, in 
sori on the under surface of the segments or pinnules. 
VIII. — Ceratopteris, Brongn. Water Fern. 
Fertile fronds compound with narrow linear segments often 
proliferous. Sori of single globose spore-cases opening irregularly 
with an incomplete or rudimentary ring, inserted on longitudinal 
veins between the midrib and the margin of the segment in a loose 
manner. Indusium continuous and membranous, formed of the 
revolute margin of the segment. Spores large marked with con- 
centric rings. Name from horn-like form of divisions ot frond. 
C. thalictroides, Brongn. (Meadow-rue leaved Water Fern). 
An annual aquatic or subaquatic tufted fern, fronds bi-tri-pinnate 
the fertile ones six to eighteen inches high, the secondary or tertiary 
pinnai short, with few distinct linear segments three-quarter to 
above one inch long, the revolute margins enclosing the fructification 
the whole length. Barren fronds distinct, shorter and more spread- 
ing, with fewer short broad variously shaped segments, flat and of a 
soft half succulent texture usually of a light color. Spore-cases 
in the Australian form with a broad nearly complete ring. 
Plentiful in^ and around m(any of the swamps of tropical Queens- 
land,^ both in water and on the damp land ; a few years ago 
plentiful near Brisbane, also found in North Australia. 
