11^3_ 
— e^? 
THE GENERA AND SPECIES OF CULTIVATED FERNS. 
131 
bi-tripinnate. Rhizome creeping. — This genus appears difficult to distinguish from some already alluded to 
except by the form of the fertile frond. In habit and venation it is si mi lar to many species of Stenochkena, 
but is separated chiefly on account of the formation of the fertile fronds. From Elaphoglossum it is distinct 
in habit, although somewhat analogous in venation ; 
distinguishable, however, by the veins being external, 
those of Elaphoglossum being internal. There are 
many species belonging to the genus, all tropical, but 
only one is in cultivation. Fig. 2-i represents a pin- 
nule of the sterile frond, and the upper portion of the 
fertile frond, of P. eylhidrica. 
1. P. cylindrica, Kaulfuss. — A coarse-looking scan- 
dent evergreen stove fern, from Jamaica and South 
America. Sterile fronds glabrous bi-tripinnate, two 
to two and a half feet long ; pinnules oblong- 
acuminate, somewhat cuneate at the base, bluntly 
lobed or dentate, bright green, and shining ; stipes 
scaly. Fertile frond contracted, bi-tripinnate, erect; 
segments terete, sporangiferous throughout. Both 
forms are lateral, adherent to a creeping rough scaly 
rhizome. This species is found in its natural habitats, 
climbing to the height of twenty feet or upwards on the 
trunks of trees. 
Sect. II.— Symplophlebiea?, J. Smith. — Veins netted. 
eLFERSIA, Raddi. — Xame probably commemorative 
of Olfers, a German writer. 
Sori amorphous, densely covering the segments of 
the fertile frond throughout. Veins forked, parallel, 
internal, their apices com- 
bined by a transverse contin- 
uous marginal vein. Fronds 
pinnate. Rhizome creeping. 
— This very elegant fern, the 
only species of the genus in 
cultivation, attains the height 
of two or three feet. In 
consequence of the fertile 
frond being contracted, and 
sporangiferous on both sides, 
it does not admit of the vena- 
tion being seen ; but in the 
sterile frond the venation is 
evident, and indicates a deci- 
sive character, by which it is 
readily distinguished, name- 
ly, the continuous, marginal, i'<!l- 25. 
transverse vein, connecting all the oblique veins by their apices. Fig. '15 represents a 
pinna of the sterile frond, and a portion of the fertile frond of 0. ccrvina (med. size). 
1. 0. eervina, Prcsl: (Polybotrya cervina, Hooker tt Grcvillc). — Aver)' elegant ever- 
green stove fern, from the West Indies. Fertile fronds erect, bipinnato, from two to 
three feet long; pinna? linear sporangiferous throughout, stipes covered with long 
narrow scales. Sterile fronds glabrous, pinnate, reclining, from two to three feet long 
with oblong-acuminate coriaceous bright green pinna', rounded at the superior base ; 
the inferior truncate. The fronds arc terminal, adherent t> a scaly creeping rhizome. 
The fertile frond of this species is commonly bipinuatc; when only pinnate it becomes 
the O. eorenvadensis of R<:ddi, a so called Brazilian species, but as we have specimens 
of both fertile funis, gathered at the same time from one plant, it is obvious that they 
are only modifications of one species. 
M NETIUiU, Splitgerber (Acrostichi { Anctium, Kww). — Name derived from aneios, 
X\ lax i alluding to the sori being sparse and scatter d. 
Spore cases lew, and regularly scattered throughout the under sin face of the fronds, 
often collected in small groups or lines. Venation uniform, reticulated; arcolcs elongated. Fronds simple; 
ruizome creeping. — The habit of this genus, (which contains but one species), and the few scattered sporangia, 
f 
