356 
FERNS : BRITISH AND FOREIGN. 
■with farinose fronds, commonly called Gold and Silver 
Ferns, are also very susceptible of moisture; they 
should never be syringed, or water allowed to fall on 
their fronds, as the farina, being loose, is disturbed by 
the water, and running down, gives the appearance as 
if the plants were smeared with dust. They, however,, 
differ from the preceding, requiring more light, and 
the temperature of the Tropical House. The species 
of Gymnogramvia vary very much in habit, as regards 
size and circumscription of the fronds, G. trifoliate 
having fronds from three to four feet high, while in 
G. chcerophylla and G. leptophylla they are fragile, and 
average from two to six inches in length. These two- 
species are peculiar in being, with the exception of 
Ceratopteris thalictroides , the only known truly annual 
Ferns. G. clicerophylla grows freely ; its spores vege- 
tate abundantly throughout the house, often as a 
weed. G. leptopliylla is, however, not so free in its 
growth. "When its fronds decay, the pot should be 
covered with a piece of glass, and put in a dry place 
until the proper season arrives in spring, when the 
application of moisture will cause the latent spores to 
vegetate. G. fiexuosa differs from the whole of the 
genus in having prelonging fronds, which climb in a 
rambling manner over bushes, like those of Lygo- 
dium, noticed in another page : it will probably here- 
after form the type of a distinct genus. The beautiful 
genus Lindscea, of which no less than sixty species are 
described in Hooker's “ Species Filicum," are, with 
few exceptions, natives of the tropics of both hemi- 
spheres; in my Catalogue of 1857, only two species are 
recorded as being cultivated ; but, within these few 
years, the number has increased to fourteen, the greater 
