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 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, 40