botany of tropical Africa is opened up to us, the more we find 
there of species previously supposed to be exclusively of Ame- 
rican or Indian origin. It is one of a group of Gymnogramme, 
distinguished by the presence of pulverulent yet ceraceous sub- 
stance, sometimes white and sometimes golden-yellow ; the first 
are called by cultivators “ Silver,” the other “ Golden Ferns.” 
But here, as I have had occasion to observe on some other 
Ferns with this exudation on the under surface of the fronds 
(see our figures and description of Cheilanthes argentea, Hk. Vil. 
Exot. t. 95), the colour varies from white to yellow and golden 
colour, and here giving rise, I suspect, to the formation of new 
species. Specimens T take to be G. chrysophylla, Kaulf., 1 can- 
not distinguish but by the colour of this substance; but now 
that we find the two colours on one and the same plant, and 
even on one and the same pinna, and well defined, it will, I 
presume, be found necessary to unite them. But to this subject 
I hope to return again ere long, for it deserves further conside- 
ration. 
Our figure represents what may be looked upon as the normal 
form of the species, but, like many other Ferns of large geo- 
graphical range, it differs much in size (often four feet high 
even in cultivation), and with pinnules varying exceedingly in 
length and breadth, and in the outline of the margin more or 
less incised or pinnatifid, in texture from membranaceous to 
coriaceous, and in the plane or reflected edges. Different as the 
ordinary form of G. ¢artarea, Desv. (Hemionitis dealbata, Viild.), 
may be from this, I find intermediate states which are very 
puzzling; and I possess not a few specimens proving that the 
white under side sometimes assumes a rich and uniform golden 
colour in G. ¢arlarea. 
Prats 50. Fig. 1 and 2. Stipes and portion of a fertile frond of Gymno- 
gramme calomelanos, Kaulf.,—naturad size. 3. Pinna, with golden and white 
pinnules; from the Oxford Botanic Garden, secn from beneath, —natural S12 
4. Upper side of pinnule, showing the venation. 5. Under side of a fertile pin- 
nule,— magnified. 
