XXXI. ADIANTUM. 
49 
The species of Gymnopteris mostly agree in habit with Cijrtogoniwn ; but they are distinguislied 
by the more irregular and compound anastomosing 
of the venules. The genus contains ten or twelve 
species, but only three are atjjresentin cultivation. 
Fig. 31 represents a portion of the sterile frond, 
and a pinna of the fertile frond, of G. nicotiance- 
folia (med. size). 
1. G. REVOLUTA, M. and if. (Hymenolepis, Blumc ; 
Hyalolepis, Kimze ). — A singular-looking evergreen 
stove Fern, from Java. Fronds simple, glabrous, 
linear-lanceolate, nearly a foot long, light green, con- 
tracted and soriferous on the upper half, attenuated at 
the hase, entire at the margin, becoming revolute, and 
partly concealing the sori during the early stages of their 
development. Fronds lateral, articulated with a slender 
creeping rhizome. We are indebted to G. Norman, 
Esq., of Hull, for a cultivated specimen of this very re- 
markable Fern. 
2. G. DECURRENS, Fee (Leptocuilus, Blume ). — A 
singular evergreen stove Fern, from Ceylon. Sterile 
fronds simple, glabrous, a foot long, lanceolate-acumi- 
nate, attenuated at the hase, light green, and slightly 
undulated. Fertile fronds simple, slender, linear, very 
narrow, one to two feet long, and one-eighth of an inch 
broad. Stipes one-half the length of the frond. Sori 
linear, continuous, forming a row on each margin. 
Both forms are lateral, articulated on a creeping rhizome 
about the size of a crow’s quill. 
3. G. nicotianjefolia, PmZ(AcROSTicnuM, 
— An ornamental evergreen stove Fern, from the West 
Bi'j. 31 . 
Indies. Sterile fronds glabrous, triangular, pinnate, one to two and a half feet long, bright green, and shining ; 
pinn® large, rather membranous, oblong-acuminate, undulated, the lower petiolate, and roundish at the base, 
the upper sessile, adnate on the lower side. Fertile fronds erect, pinnate, or occasionally hipinnate below, 
one to two feet high ; pinn® oblong-ovate, the lower petiolate, the upper sessile, adnate at the inferior base. 
Stipes scaly near the base. Both forms are lateral, adherent with a creeping rhizome. 
4 
Trile Pteeide^, J. Smith . — Sori parallel with and situated on or near the margin or the costa, 
and furnished Avith a special indusium, having its inner margin free. 
Ferns are very obviously divided into two groups, in one of which the sorus is furnished with a 
membrane, which at first completely covers it, and is termed an indusium or involucre ; and in the 
other the sori are naked or without iudusia. The PolypocUece and AcrosticJieee form the non-indusiate 
group. The Pteridecs belong to the group which jiossess an indusium, and are characterized by having 
that oi'gan produced on the exterior side of the sporangiferous receptacle, with its inner margin free, 
and with the spore-cases in its axis of attachment, or on its inferior disc. This tribe is represented 
by the genera Adiantuni, Pteris, and Bleclmiim, of older authors, and is at once distinguished from 
Polypodies and Acrostiches by the presence of the indusium, although closely allied to the latter tribe, 
through the genus Lomaria. 
Sect, CniLosoREiE, J. Smith (from cheilos^ a lip, and sorus .) — Sori marginal, continuous, or interrupted. 
XXXI. ADIANTUM, Linneeus. 
Sori round reniform oblong or linear, marginal, continuous or interrupted. Indusium venose, 
formed of a reflexed crenule, reniform oblong or linear, according to the more or less crenulate or 
H 
