4 PHANEROGAMS AND FERNS OF SOUTH ARDGOIL. 
and Coilessan. This belt extends up the hill slopes for vary- 
ing distances, but generally from four hundred to six hundred 
feet, and sends tongues of woodland up the banks of the 
streams to about one thousand feet, a height reached usually 
by the birches. This woodland belt consists mainly of birch 
and oak, the oak occasionally being predominant, but usually 
the birch, and mixed with these are frequent isolated hazel, 
hawthorn, alder, holly, ash and rowan. The greater part of 
the wood consists of trees about fifty years old, with occasional 
older trees here and there, especially holly and hawthorn. 
On the slopes of Corran Bay there is a strong development 
of alder, the birch disappearing, so that the wood consists of 
alder, oak and hawthorn. Where birch and oak dominate, as 
is generally the case all round the coast, the shade of these 
trees is slight, so that bright light penetrates to the ground ; 
but where hazel and alder dominate, as is the case only in this 
half-mile, the shade is dense and the ground flora is different. 
The type plant of the birch and oak wood is the bracken, and 
that of the hazel and alder the mountain shield fern—the 
bracken being a light-loving fern, whereas the mountain shield 
fern must have almost continuous shade. These two types 
are accompanied by other characteristics. The dense shade of 
the one allows usually only a sparse vegetation, the loose, 
moist earth in many places being almost bare, whereas the 
open canopy of the other favours a more plentiful growth. 
The following are three lists from the oak wood, each for a 
small area :— 
1. Pteris aquilina. 2. Pteris aquilina. 
Aspidium Oreopteris. Oxalis Acetosella. 
Blechnum boreale. Lysimachia nemorum. 
Potentilla Tormentilla. Circa lutetiana. 
Oxalis Acetosella. Primula vulgaris. 
Teucrium Scorodonia. Agraphis nutans. 
Aspidium Oreopteris. 
3. Pteris aquilina, 
Aspidium Oreopteris. 
Galium saxatile. 
Oxalis Acetosella. 
Agraphis nutans. 
Anthoxanthum odoratum. 
