126 VEGETATION OF THE PEAK DISTRICT [CH. 
Lime-loving, on the Humus-loving, on the 
whole whole Ubiquitous 
Arenaria verna Pteris aquilina Botrychium Lunaria 
A. serpyllifolia Potentilla erecta Ranunculus bulbosus 
Thlaspi alpestre P. procumbens Lotus corniculatus 
Arabis hirsuta Ulex Gallii Linum catharticum 
Poterium Sanguisorba | U. europaeus Viola lutea 
Anthyllus Vulneraria | Lathyrus montanus Conopodium majus 
Helianthemum Cha- Polygala depressa Gentiana Amarella 
maecistus | Galium saxatile Veronica officinalis 
Sedum acre Erica cinerea Plantago lanceolata 
Gentiana baltica Calluna vulgaris Crepis virens 
Thymus Serpyllum Vaccinium Myrtillus Hypochaeris radicata 
Plantago media V. Vitis-idaea Leontodon hispidus 
Galium verum Deschampsia flexuosa | Hieracium Pilosella 
G. sylvestre Nardus stricta Anthoxanthum odora- 
var. nitidulum Juncus squarrosus tum 
Carlina vulgaris J. effusus Agrostis vulgaris 
Carduus nutans forma compactus Briza media 
Avena pubescens Luzula multiflora Festuca ovina 
Koeleria cristata (agg.) forma congesta Carex flacca 
Luzula campestris 
PsEUDO-CALCAREOUS HEATHS 
The true calcareous heath should not be confused with the 
alternation of lime-loving and humus-loving species where this 
alternation is due to the occurrence of non-calcareous detritus 
or drift in a chalky or limestone district. Such a tract of 
vegetation is made up of the mixture of small societies or 
associations belonging to two or more plant formations, just as 
the terrestrial vegetation of small islands dotted about a lake 
differs from the aquatic vegetation in the lake itself. The true 
calcareous heath occurs on soil where there is no drift or foreign 
soil of any kind; and the transitional nature of the vegetation 
is due to a secular and gradual change in the nature of the 
primitive, calcareous soil. 
Again, many of the higher summits of that portion of north 
Derbyshire which is indicated, on the geological maps, as 
consisting of Carboniferous Limestone are capped by a layer 
of non-calcareous chert; and on this, of course, normal siliceous 
grassland and moorland frequently occur. 
