Apri 1906.] NOTE ON RHACOMITRIUM RAMULOSUM. LOL 
apart: by Dr. Stirton in Lewis in 1901, and by Mr. Lillie in 
Caithness. 
According to the authors it is very closely allied to 
heterostichum, which is a very variable moss. Slender, and 
more slender, elongated stems with a gradually vanishing 
hair-point bring the varieties alopecwrwm and gracilescens of 
heterostichum, and the sub-species sudeticwm and ramulosum, 
very close together. Extreme forms can be distinguished, 
but when they approach each other, as they frequently do, it 
is difficult to separate them. The chief characteristic of the 
present plant lies, as its name indicates, in the branching, for 
the stems are slender with very numerous, short, obtuse 
lateral branchlets; the short hair-point; and the long and 
very narrow leaf-cells. 
Mr. Dixon says: “Some authors unite it with heterostichum 
as a variety, but this seems scarcely justified, so long 
especially as sudeticwm is maintained as a separate species : 
1 cannot but think that the elongated upper areolation in 
ramulosum is a character of greater importance than any 
which separates the former from heterostichum. It must, 
however, be admitted that this character is less constant and 
uniform than one could wish, and it is perhaps better to treat 
both sudeticwm and ramulosum as sub-species of heterostichum. 
In habit ramulosum resembles fusciculare to some extent, and 
in the densely nodose branching it even approaches canescens, 
while the hair-point is occasionally so developed as to render 
the plant quite hoary: the areolation and the presence of a 
hyaline point combined make it easy of recognition: in the 
fruiting characters it is near swdeticwm, but the capsule is 
longer and darker, while the habit is quite different. So 
much doubt exists as to the plant intended by Bridel to be 
described by his name microcarpon, that it seems safer, and is 
far less confusing, to use Lindberg’s name for the present 
species and sudeticwm for the second of the two plants to 
which Bridel’s name has equally been applied.” 
A sheet with all the British species and varieties of the 
genus Lhacomitrium was exhibited. 
