ROBERT SMITH ON PLANT ASSOCIATIONS OB' THE TAY BASIN. 207 
on. It is a familiar fact that, in certain parts of our district, it is only 
necessary to protect the vegetation by means of enclosure to ensure 
the natural growth of many seedling trees. In 1829, 300 acres were 
thus enclosed by the Duke of Buccleuch on his estate in Selkirk¬ 
shire ; soon afterwards a luxuriant tree vegetation, chiefly of birch, 
hawthorn, rowan, pine, and willow, grew up (Farquharson). We may 
all have noticed amongst the heather on the moors numerous young 
plants of pine, birch, willow, and rowan nibbled down year by year 
by the grazing sheep. Wherever sheep are pastured the same fact 
has been recorded (Darwin in Surrey, Flahault in South France, 
Krause in Germany, etc.). 
Of course, before such a natural regeneration could go on, there 
must be some old pine trees in the neighbourhood to form seed. 
How far the winged seeds of the pine can be carried still requires to 
be more precisely noted, but it does not seem to be very far. The 
most reliable statistics are those by Fliche, who puts 115 metres as 
the greatest distance to which seed can be borne from the parent 
plant. 
The following list of the associates of the pine has been made up 
from notes on pine woods near Stanley, Bankfoot, Dunkeld, Lundie, 
etc. It has been compared, and on the whole found to agree in 
character, with my own lists for Norway, and with those given by 
Warming, Hock, etc., for Denmark, Germany, and Russia. 
PLANT ASSOCIATION OF SCOTS PINE WOODS. 
(Larch and Spruce are often planted with the Pines, and Birch, Elm, 
Ash, and Aspen occur self-sown. 
Rununculus acris, L. 
Viola silvestris, Reich. 
Potentilla silvestris. Neck. 
Galium saxatile, L. 
Scabiosa succisa, L. 
Carduus palustris, Willd. 
(In marshy ground.) 
Vaccinium Myrtillus, L. 
V. Vitis-Idaea, L. 
Calluna Erica, D.C. 
Erica Tetralix, L. 
(In marshy ground.) 
Pyrola minor, L. 
Euphrasia officinalis, L. 
Salix repens, L. 
Empetrum nigrum, L. 
Juncus conglomeratus, L. 
(In marshy ground.) 
Luzula campestris, D.C. 
Agrostis vulgaris. With. 
Deschampsia caespitosa, Beauv. 
D. flexuosa, Trin. 
Holcus lanatus, L. 
Festuca ovina, L. 
Dicranum scoparium, Hedw. 
Polytrichum commune, L. 
Plagiothecium undulatum, L. 
Juniperus communis, L. 
Lomaria Spicant, Desv. 
Lastraea Filix-mas, Presl. 
This association stands in direct contrast to that of the beech. 
Here shade-plants are almost awanting, and the flora is essentially 
p 
