Dicksonia. 
1 1 
DICKSONIA CULCITA, L'Heritier. 
This is a large and handsome fern, though, compared with some other species of the genus, 
it is quite of humble stature. The caudex, indeed, is small, only three or four inches high, 
rooting, with the end deflexed, and thus gives none of the tree-life character so characteristic 
of some of the congeners of the plant. It is, however, remarkable in being quite without the 
ordinary paleae or scales, but instead is very thickly and densely cushioned, especially at the 
apex, with a mass of long, golden-orange, shining hairs, which are over an inch long, and under 
the microscope are seen to be jointed. The fronds are of large size, attaining a length of four to 
six feet, and arching outwards, they are supported on a long stipes, which is perfectly smooth 
and devoid of paleae or hairs, shining and pale brown ; in form the stipes is bluntly angular, and 
so much channelled along the upper surface as to be thin and crescent-shaped in section, when 
a single curved bundle of vessels is seen. The form of the frond is rather broadly triangular, 
but drawn out at the apex ; it is much divided, quadri-pinnate, coriaceous, dark green, and 
perfectly smooth. The primary pinnae are wide-spreading and ovate-acuminate in outline, the 
secondary ones rather ovate-oblong, and frequently much attenuated at the point ; whilst the 
ultimate divisions are oblong, rather obtuse, oblique, and deeply pinnatisect ; the segments (at 
least, the lower ones and those without sori) bluntly dentate, with a few thick teeth. The 
venation is simply forked. 
It is, however, the sori that are particularly noticeable, as they are usually produced 
in great abundance. They are large, nearly one-quarter of an inch in diameter, sub-globose, 
and each one occupies nearly the whole segment, which then, instead of being toothed, is 
dilated, and with a rounded deflexed margin. Their structure is peculiar, and differs from 
that of all the other European ferns. The very large, thick, brown indusium is attached by 
a semi-lunar base below the sorus, and at first is united by its upper edge to the deflexed 
margin of the segment, so that the whole forms a thick marginal case, rounded, but flattened on 
the top. Afterwards this separates, and the indusium exhibits an entire semi-circular free 
margin, or lip, whilst an upper lip is formed by the margin of the segment ; at length the 
lower lip becomes separated also at the sides and deflexed. The sporangia are small, very 
numerous, on long stalks, bright yellow, and mixed with many brown barren filaments 
(paraphyses) ; they open by a transverse chink, and possess a complete oblique annulus. 
A special interest attaches to this fern from its being the only member of the great 
tropical group of the Cyatheaccce which reaches Europe. Its footing, indeed, on this continent 
is but slight, consisting of, as far as known, but a single locality in Southern Spain, discovered 
in 1869. This is near Algeciras, the little town which faces Gibraltar across the bay. 
The head-quarters of D. Culcita are, apparently, in the Azores Islands, where it is very 
abundant in the woods, especially at an elevation of from 2,000 to 3,000 feet. There are specimens 
in the British Museum from S. Miguel, collected by Masson so far back as 1778. In Madeira 
the plant is not now common, being chiefly found near S. Vincent and on the north-west side 
of the island. When we add Teneriffe to its localities, we have traced the whole range of this 
species, which will be thus seen to be a marked member of that peculiar Atlantic flora of which 
a few species reach our western shores. The fern does not occur in the Canary Isles ; and 
the species from the mountains 01 Central America and the West Indies, often referred to 
D. Culcita, is an allied species — D. coniifolia, Hook. 
Another name for this fern is Balantium Culcita, Kaulf. 
