270 BRITISH PLANTS . 
deep marly soils. The birch is also common in the 
lowlands, but in the uplands it beats all trees, and ulti- 
mately entirely supplants the oak, ash, and beech at the 
higher altitudes of tree-growth on all kinds of soils. From | 
the great admixture of other trees competing with the 
oak for dominance, these woods are often called mixed 
deciduous woods. The hazel is the most common shrub 
of the undergrowth, and in woods periodically cut oak- 
hazel coppices are formed. 
Vegetation of the Damp Oak-Wood—1. Trees.—Quercus 
Robur (= pedunculata, with stalked acorns) is the dominant 
tree on deep soils, Q. sessiliflora (with sessile acorns) on 
shallow soils; ash, birch, beech, hornbeam; and of trees 
commonly planted—sweet chestnut, sycamore, poplars, 
lime, and elm. 
2. Shrubs.—Hazel (most abundant), maple, sloe, haw- 
thorn, elder, bramble, wild rose, honeysuckle, sallow- 
willow (Salix Caprea), holly, dogwood, and guelder-rose. 
3. Herbaceous Undergrowth.—Anemone nemorosa, Pri- 
mula vulgaris, Scilla nutans (on loose soils), Mercurialis 
perennis, Ranunculus Ficaria, Euphorbia amygdaloides 
(wood -spurge), Stellaria Holostea (greater stitchwort), 
Oxalis Acetosella, Viola sylvatica, Sanicula europea, 
Geranium Robertianum, Epilobium montanum, Lamium 
Galeobdolon, Lysimachia nemorum (yellow pimpernel), 
Nepeta Glechoma, Lychnis dioica, Ajuga reptans, Prunella 
vulgaris ; woodland - grasses: Milium efiusum, Bromus 
giganteus, Brachypodium sylvaticum, Melica uniflora, ete. ; 
ferns: Aspidium Filiz-mas, Athyrium Filix-femina, and 
in light soils Pteris aquilina. 
(6) Upland Type.—A dry oak-wood is found on dry, 
non-calcareous soils at an altitude of 500 to 1,000 feet. 
The wood is more open than on the lowlands, and this 
favours a thick shrubby undergrowth and a luxuriant 
ground-vegetation. But this diminishes as the soil 
becomes drier and the altitude increases. The soil is 
deficient in humus, and the undergrowth includes a small 
proportion of heath-plants (ling, gorse, bracken, etc.) 
exhibiting xerophytic characters. As the altitude in- 
creases birches gradually succeed in dominating the oak, 
and at about 1,000 feet the oaks disappear altogether, 
while the birches continue up to the limit of tree-growth 
(1,500 feet in England). The ash is absent, and likewise 
