Vegetation of the Island of Gothland. 267 
Among some of the pine-woods numerous remains of small 
peaty lakes occur ; where the water had disappeared and the former 
lake-bottom was covered with grass, seedlings of pine and juniper 
were common (cf. PI. V, fig. 2) and the forest seemed to be spreading 
over the whole tract. It would seem likely then that much of the 
present pine forest belongs to the fen succession. The occurrence 
of pine on these tracts, and also as a colonist of the calcareous bogs, 
indicates clearly that it is by no means a calcifuge. But the typical 
pine forest occurs on the sandy soil, tracts of which are found 
everywhere, and here it probably forms the ultimate stage of the 
psammophilous plant succession. The trees are chiefly Pinus 
sylvestris with but little spruce and birch. Shrubs are represented 
by Junipcrus communis and Taxus. The ground flora contains Pteris 
aquilina, Calluna vulgaris, Epilobium angustifolium, etc. in the 
shadier woods. A number of species of Pyrola occur, and on the 
roadside banks through the woods I noticed much Vaccinium Vitis- 
idcea, Cotoneaster integerrhna and low creeping masses of Arctosta- 
phylos. The ground is often covered with creeping Ivy. The woods 
grow right on to the sea-cliffs in some places, but near the sea the 
trees show a stunted appearance and isolated trees often have a 
marked one-sided growth. In one of the dry woods on a very stony 
soil on the cliffs, there were a great many plants of Epipactis 
rubiginosa and also much Anemone hepatica. 
In the more open places on the dry sandy soil we see many 
typical xerophytic plants with enormously well developed root 
systems. Exposures of bare sand support only a few plants such 
as Scleranthusperennis, Rumex Acetosella, Sedum album, etc. Where 
the vegetation was less open Gnaphalium sylvaticum occurred in 
large quantities, with Erythrcca, Centaurium Fragaria vesca and 
numerous grasses (e.g., Agrostis canina). In the spring ephemerals 
such as Veronica verna grow here. 
Rock Plants. 
In many places the surface of the underlying rock projects 
through the covering of sandy drift and forms a very unfavourable 
substratum for plants. These spots, however, support vegetation 
of an interesting type. The first plants to obtain a footing in the 
cracks of the bare rock are mosses, quickly followed by Sedum album, 
The latter is very abundant on the barest places : its prostrate 
stems creep over the surface bearing the reddish fleshy leaves and 
conspicuous inflorescences and sending down adventitious roots 
