RHODOSPERME. 201 
all the branches being set with an opposite series of spreading pinnules, 
which are closely pectinated, or set on each side with comb-like teeth, 
which gradually diminish in length towards the tips of the little branchlets. 
In luxuriant specimens the branches sometimes put forth a second and 
even a third series of branchlets, as seen in our illustration, and all of 
them are furnished with the pretty characteristic pectinated ramuli of 
this elegant species. Spores are contained in clusters of favelle, which 
are produced within little stalked involucres, and these are mainly com- 
posed of several tiny clasping or incurved ramuli. These involucres are 
set along the stems of the ultimate branches alternately with the pectinated 
ramuli, and sometimes they are produced on the teeth of these little 
comb-like pinnules, as represented in the illustration. Tetraspores, 
which are very rare, are produced on the teeth of the ramuli. A very 
splendid form of this plant is abundant on the Australian shores, and 
another, equally beautiful, on the North American coasts. The specimens 
which are taken on the Irish coasts, and in the Isle of Man, have long 
lanceolate branches, with very short pinnules, and, although of very 
Fic. 187. Ptilota elegans. 
elegant growth and brilliant colour, are by no means so luxuriant and 
bushy as our North British specimens. This species does not readily 
adhere to paper. The fronds are very rigid, inarticulate, and of a more 
or less cartilaginous structure; but the branches being compressed, or 
of a very flat growth, they are easily displayed on paper, and with a 
little judicious pruning and the application of disso] ved isinglass, they make 
some of the most attractive of our book specimens. P. elegans (Fig. 187), 
formerly P. sericea,is a much more delicate plant than the foregoing. The 
fronds are soft and silky to the touch ; but they are usually so excessively 
and densely branched, that considerable pruning is necessary before a 
specimen can be effectively displayed. The manipulator is, however, well 
repaid for any amount of patience in arranging this plant, for it is 
assuredly one of the most beautiful of the British rhodosperms. Although 
the stems and principal branches are dark in colour, and of rather dense. 
structure, the branchlets and pinnules are distinctly and beautifully 
jointed, as may’ be seen in Fig. 187, which represents two ultimate 
T 
