A HISTORY OF DERBYSHIRE 



tion reach their limit. This zone includes the higher levels from about 

 1,100 feet in the central part of the county and 900 feet in the Peak to 

 1,750 or i, 8 oo feet. Characteristic plants are holly (Ilex aquifolium), 

 hawthorn (Crateagus oxyacantba], bramble (Rubusfruticosus], honeysuckle 

 (Lonicera periclymenum), ash (Fraxinus excelsior) and oak (>uercus robur] ; 

 of alpine plants Draba incana is found as low as 800 feet, bearberry 

 (Arctostaphylos uva-ursi) at 1,250 feet, bracken reaches 1,650 feet on 

 Axe Edge and nearly the same level on the moorland above Glossop. 



Our next and highest zone is the infer-arctic, where bracken 

 (Pteris) ceases and cross-leaved heath (Erica tetralix) reaches its limit. 

 This embraces the high moorland above the 1,750 feet level, the highest 

 points being Bleaklow Stones, 2,060 feet ; Kinderscout, 2,031 feet ; 

 Crowden Head, 2,070 feet ; a point near it marked 2,088 feet on the 

 ordnance map ; Kinderlow, 2,077 feet. Characteristic species are cloud- 

 berry (Rubus chameemorus], mountain ash (Pyrus aucuparia), Vaccinium 

 Vitis-idcea, cranberry (V. oxycoccos), bearberry (Arctostaphylos uva-ursi), 

 Andromeda polifolia, heather (Calluna -vulgaris), crowberry (Empetrum 

 nigrum), lesser twayblade (Lister a cordata], Habenaria albida, moor rush 

 (Juncus squarrosus). 



PHANEROGAMIA 1 



BOTANICAL DISTRICTS. The other factor dealt with here is that of 

 rocks and soils. The botanical divisions are based upon the surface 

 geology so far as possible, as will be seen. Beginning with the oldest 

 formation the mountain limestone occupies the west central district, 

 interpolated here and there with sheets of contemporaneous lava (toad- 

 stone). It has a few small outliers at Ashover and Crich eastwards, at 

 Snelston Common southwards, and another more distant at Ticknall and 

 Calke south of the Trent. The well known dales on its west, north 

 and east borders are the result of the action of water. The main 

 plateau rises here and there into rounded hills, the dales present tiers of 

 wall-like cliffs along their sides, and in them the characteristic flora 

 abounds. This stratum is succeeded on all sides by the Yoredale 

 shales, best seen at Mam Tor above Castleton. These are in some part 

 included with the limestone, and with it form division I. of the flora. 

 It should be added that the mountain limestone passes westwards into 

 Staffordshire. The following is a list of plants characteristic of the 

 division, those peculiar to it being marked with an asterisk : *Tbalictrum 

 minus, Linn. ; Helleborus viridis, Linn. ; Arabis birsuta, Scop. ; *Carda- 

 mine impatiens, Linn, (occasionally carried into other districts along the 

 banks of streams) ; * Draba muralis, Linn. ; *D. incana, Linn. ; *Cochlearia 

 alpina, H. C. Wats. ; *Tblaspi alpestre, Linn. ; *Hutcbinsia petraa, R. Br. ; 

 Heliantbemum vu/gare, Gaertn. ; Viola hirta, Linn. ; *Silene nutans, Linn. ; 

 Arenaria verna, Linn. ; *A. tenuifolia, Linn. ; Hypericum Androscemum, 

 Linn. ; *H. montanum, Linn. ; * Geranium sanguineum, Linn. ; G. columbinum, 

 Linn. ; G. lucidum, Linn. ; * Hippocrepis comosa, Linn. ; Spircea Jilipendula, 



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