280 
FLORA OF FORFARSHIRE. 
and when almost wholly white is fi.fallax, Hook. (C . fal- 
lax , Ach.) 
C. nivalis, Ach. Snow Cetraria. H. 221. 
Bassies ; Ben Red ; Loch Brandy ; and other of the Clova 
summits, never descending much below 3000 feet, always 
sterile. 
C. Islandica, Ach. Iceland Cetraria, (the Iceland Moss 
of commerce.) Sidlaw Hills frequent ; but more abundant 
on the Clova mountains. Moors around Forfar, Mr A. 
Croall. The ft. is rarer on the Clova mountains than on 
those of Braemar ; I picked several specimens on a hill near 
Loch Wharral, known as the “ Cat's-tae." 
Dr Davidson of Glasgow states, on the authority of Berze- 
lius, that this lichen in 100 parts comprises the following in- 
gredients : — 
Chlorophyll?, 
• • 
1.6 
Bitter principle, 
• • 
3.0 
Uncrystallizable sugar, 
• • 
3.6 
Gum, 
f s 
3.7 
Apothem of extractive, 
• • 
7.0 
Starch, 
# * 
44.6 
Bilichinates of potass and lime, &c. 
1.9 
Amylaceous fibrin, . . 
• • 
36.2 
When deprived of the bitter principle by boiling, a fine 
jelly is procured, which, when mixed with wheaten flour, 
forms, it is said, a “ perfectly sweet bread.” It is much used 
in medicine. 
Borrera, Ach. Borrera. 
Br. Sp. 7. F. 3. 
B. ciliaris, Ach. Larger ciliated Borrera. H. 222. 
Old walls frequent, as Baldovan, Mains, Auldbar, Foulis, 
&c., apothecia not uncommon. In profusion, in ft., on old 
trees at the Castle of Melgund, and on old walls half way 
between Forfar and Kirriemuir, Mr A. Croall. 
B. tenella , Ach. Lesser ciliated Borrera. H. 222. 
Old walls, ft. common. 
B. furfuracea, Ach. Branny Borrera. H. 223. 
