11] WOODLAND ASSOCIATIONS 77 
Melampyrum sylvaticum, and Cypripedium Calceolus are 
examples, though, judging from an old record, cited in Linton’s 
flora (1903 : 274), the last-named species seems to have occurred 
formerly in Derbyshire. 
The following plants are found in ash woods of Derbyshire, 
but do not occur so far south as Somerset, and are hence absent 
from woods of the ash type in the latter locality :-— 
Stellaria nemorum Campanula latifolia 
Cardamine amara Cnicus heterophyllus 
Trollius europaeus Melica nutans 
Geranium sylvaticum Festuca sylvatica 
Polemonium coeruleum Hordeum sylvaticum 
Myosotis sylvatica Carex ornithopoda 
On the other hand, the following plants occur in woods of 
the ash type in Somerset, but have not been noticed during the 
present survey in those of the hills of the Peak District :— 
Clematis Vitalba Viburnum Lantana 
Aconitum Napellus Calamagrostis Epigejos 
Euphorbia pilosa Colchicum autumnale 
E. amygdaloides Cephalanthera grandiflora 
Lithospermum purpureo-coeruleum Ornithogalum pyrenaicum 
The autumn saffron (Colchicum autwmnale) is indigenous in 
pastures on the Permian limestone; but it is not a woodland 
plant in the north of England, as it is in Somerset and 
Cambridgeshire. 
The following lime-loving and shade-loving species occur on 
the lowland Permian limestone tract to the east of the Pennines, 
but are absent from the woods of the Carboniferous Limestone 
of the Peak District :— 
Astragalus glycyphyllos Viburnum Lantana 
Galium Mollugo Calamagrostis Epigejos 
Generally, it is clear that the ash woods occurring on the 
calcareous soils of England are richer in species than the oak 
and birch woods occurring on the non-calcareous soils, and that 
of species common to both types of wood, many are more 
abundant and ascend to higher altitudes there than in the oak 
and birch woods. These facts can scarcely be held to support 
a statement sometimes made that calcium carbonate acts 
deleteriously on plants. Woodhead (1906: 396) states that 
his study of the woods around Huddersfield “indicates that in 
