108 CHARACTERS OF TRIBES AND GENERA. 
Illust. Hook. and Grev. Ie. Fil, t. 178; Hook. and 
Bauer, Gen. Fil, t. 13; Moore Ind. Fil., p. 55, A. ; 
Hook. Syn. Fil., t. 6, fig. 49, 
Oss.— This genus is founded on a very peculiar Fern, 
which on account of the reflexed margin of the pinnæ was 
referred to the genus Pteris by Swartz, but it having been 
found that the sporangium was produced in the centre of 
the pinne, in the form of a single round sorus, led to its 
being characterised as a distinct genus by Hooker and 
Greville, under the above name, in the * Genera Filicum," 
however, Sir William Hooker says that “Mr. Bauer's 
dissections, and Mr. Smith's investigations, show that there 
are several small sori, which eventually become confluent." 
This is one of the peculiar Ferns spoken of at page 12 
of the Introduction, that continue to form and develope 
pinnæ from the apex of the frond, which lengthens indefi- 
nitely as long as the plant continues to receive influences 
favourable to its growth, 
It is found only in the Andean regions of Tropical 
America, where it has a wide range, presenting different 
appearances in the various localities in which it is found: 
the different states being described by Kunze under at least 
five distinct species, which in the “Species Filicum ” are 
considered as only synonyms of J. imbricata. Mr. Spruce, 
however, who has studied them in their native localities 
informs me that he considers there are at least two distinct 
species, and also refers Gymnogramma elongata to this genus. 
Sp. J. imbricata, Hook. and Grev. Ie. Fil., t. 178 (J. sca- 
laris, Kunze Fil., t. 71; J. verticalis, Kunze Fil, t. 82; 
J. canescens, Kunze, in Schk, supplt., t. 133; J. cinnamonea, 
Kunze, in Schk. Fil. supplt. t. 71); J. elongata, Fée. 
(Gymnogramma elongata, Hook., in Journ. of Bot., 1834, 
p. 61, t. 119). cee 
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