210 
Choice Ferns for Amateurs. 
DICKSONIA— continued, 
very gLaucous, with, which the colour of the conspicuous 
spore miasses formis a pleasing contrast . 
D. squarrosa. 
A very handsome, arborescent, greenhouse species, 
native of NeAV Zealand and Chatham Island. It is particu- 
larly attractive on account of its slender, black or very 
dark-coloured trunk, which frequently produces young 
plants on its surface. The habit of its head is also 
peculiar and very effective : it is quite flat, and is formed 
of a quantity of rigid, leathery fronds, dark shining green 
on their upper surface, paler beneath, and borne on short 
and comparatively slender, dark purplish or blackish stalks 
that are covered with raised points and blackish hairs. 
These fronds are oblong-triangular and tripinnate; their 
numerous oblong-spear-shaped leaflets, 9in. to 15in. long 
and 4in. to Gin. broad, are furnished with nearly stalkless 
leafits, which in their turn are divided into spear-shaped 
segments, the barren ones toothed, the fertile ones much 
smaller, deeply pinnatifid, and contracted. The sori are 
disposed six to eight on the lower segments, the whole 
of which they occupy, with the exception of the midrib 
and the tip. The trunk of this species, being naturally 
of a very dry nature, must be carefully kept moist. 
DICTYOGRAMME. See Gymnogramme. 
DICTYOPTERIS. See Polypodium. 
DIDYMOCHLiENA. 
Only a couple of species are embraced in this 
genus, both being of tree-like habit. They 
are very ornamental, stove Ferns, and especially is 
this the case with D. lunulata, which is most com- 
monly met with in collections. They are of easy 
cultivation, although it is nothing unusual to see 
their leafits fall of, leaving the stalks naked; that 
generally happens when the plants have suffered 
from want of water at the roots; but although un- 
sightly for a time when in such condition, they 
soon recover under liberal treatment. The plants 
should be potted in a mixture of two parts of good 
fibrous peat and one of loam, with a good dash of 
silver sand, and be thoroughly well drained; 
although they naturally grow in places that are 
constantly moist, stagnancy at the roots must be 
