LICHENS IN THE ISLAND OE BUTE. 
83 
grassy banks beneath the hedges or palings, and on stopping to 
look into it we find growing amongst the moist grass a rather 
larger lichen Peltigern canina, of a deep olive green above and 
almost white beneath, but we find it pretty firmly attached to 
the grass by a number of white rhizinae or root-like appen¬ 
dages, which are not really roots, but are evidently only 
means of support, like the tendrils of climbing plants. From 
the edges of the tliallus finger-like lobes may be seen standing 
upright, upon the ends of which are fiat round discs of a 
dark brown colour. These are the apothecia, and bear the 
asci and spores. When dry the plant looks very different in 
colour ; the olive green all disappears, and the tliallus goes 
into a light brown or grey colour. 
If we now notice the trunks of the trees we find them 
abundantly mantled with a whole galaxy of lichens. Let us 
look more closely at some of them. 
There is the grey beard-like Usnea barbata , of a pale sea- 
green shade, with its long threads growing into tangled tufts; 
through the centre of each runs a white thread, being the 
medullary layer; a whitish powder, the soredia, is often 
scattered over the fine branches, which gives a very soft 
appearance to the plant, thus much heightening its effect in 
ornamenting the forest trees. Its fruit is terminal, and the 
disc is surrounded with a row of barbs; hence its name barbata. 
Near it we find a somewhat similar lichen, but much 
firmer in texture, i.e., cartilaginous. Its branches are flat¬ 
tened, and not so fine nor so intricate as in Usnea , but they, 
too, are often extensively covered with patches of mealy 
soredia, which give the name to it— Ramalina farinacea , and 
it is very rarely found in fruit. 
Near it there is another of the same genus— Ramalina 
fastigiata —which is abundantly in fruit, and, as its name 
implies, it is a small variety with a number of short branches 
closely packed together. 
Our attention is next arrested by a whole cluster of very 
pretty, though rather shaggy-looking lichens, almost covering 
the branches of a tree. This is Evernia prunastri. Its soft 
limp tliallus is flat and cut into a number of branching lobes, 
called lacinias. It is glaucous on one side and snowy white on 
the other, and is one of the most plentiful lichens on the trees 
of our woods and the palings of our country lanes. 
There is another Physcia growing on the trees, but it is so 
near the colour of the bark and is so closely appressed that 
you will have to go close up to find it. The centre is often 
crowded with the little cup-like apothecia, while both they 
and the tliallus are covered with a fine powder. Hence its 
name— P. pulverulenta. 
