Hart — On the Mountain Flora of Ireland, 
655 
On page 548 : — 
Osmunda regalis, 
Ophioglossu7n vulgatum^ 
decreases 300 from II. to X. 
JBotrychium lunaria reaches an unusual heiglit on the Derry trap- 
rocks, as do several other species. 
The plants enumerated ahove are all those with an upward 
limit {a). Viewed with regard to their powers of existing on moun- 
tains all plants may be regarded as falling within one of five divi- 
sions. They have either : — 
{a) An upward limit. 
if) A downward limit. 
{c) An upward and a downward limit. 
\d) Ko limit. 
{e) No mountain existence. 
The Irish flora consists of about 1000 species. 600 of these, 
therefore, fall under (^), and are excluded. In {d) we have those 
species which reach all summits (or very nearly so) in Ireland. 
These are : — 
A few of these, as the two Carices, Anthoxanthum and the two 
Lastreas are somewhat doubtfully included here, as they require 
more moisture and shade than all summits can afford, and some of 
them seem to have upward limits in the northern counties. One or 
two others might perhaps be regarded as summit plants, as Viola 
sylvatica and Cerastium triviale. 
Potentilla tormentilla, 
Galium saxatile^ 
Campanula rotundifolia, 
Calluna vulgaris^ 
Melampyrum pratense^ 
Euphrasia officinalis, 
Rumex acetosa, 
M. acetosella, 
Empetrum nigrum, 
Juncus squarrosus, 
Zuzula sylvatica, 
L. campestris, 
Bcirpus ccespitosus, 
Carex stellulata, 
C. pilulifera, 
Anthoxanthum odoratum, 
Agrostis vulgaris, 
Aira flexuosa, 
Festuca ovina, 
Lastrea filix-mas, 
L, dilatata, 
lilechnum horeale, 
Hymenophylluni unilaterale, 
Lycopodium selago. 
2 Q 2 
