Page:VCH Berkshire 1.djvu/95

 BOTANY the dwarf willow (Sa/ix repens] or occasionally the gregarious bilberry (Vaccinium Myrtillus}. In other places monotonous tracts yielding little besides the sombre grass Molinia varia occur. In the short turf, especially of the riding through the pine woods where there is good sun exposure, we may pick the local Hypochaeris glabra, Teesdalia nudicaulis, or Ceras- tium quaternellum (Maencbia), and it will often be found studded with the beautiful blue flowers of Myosotis collina or the dainty Ornithopus perpusillus. Instead of the buckthorn of the chalk and limestone we have the genus represented here by the alder buckthorn (Rhamnus Frangula) ; instead of the oaks and elms and beech we have the pine, not indeed as a native but as a replanted tree. The Molinia grass replaces the wood barley (Elymus] and the Milium eff'usum of the chalk woods. The violets here are not the hairy and sweet violets (Viola hlrta and odorata) of the chalk and oolite, but V. palustris and V, lactea. Instead of the butterwort (Pinguicula)., the sedges Carex dioica, C. vulpina and C.fu/va, the orchid Epipactis palustris of the calcareous bogs, we have in this more acidulated peat water .the sundews Drosera rotundifolia and D. longifolia, the sedges Ryncbospora alba^ Scirpus ccespitosus^ Carex data and C. canescens, and the Lancashire asphodel (Nartbecium) . The pondweed Potamogeton polygonifolius here takes the place of P. natans, so common in the ponds north of the Kennet, while P. alpinus replaces P. prcelongus in the streams. In the northern bogs the cotton grass is usually Erio- phorum latifolium, in these it is E. angustifolium. The ponds in the north have usually a coarse vegetation in which Bidens tripartita is often fre- quent ; in these B. cernua is more likely to occur. Instead of the Charas C, fragi/is, C. bispida and C. contraria of the north, here they will probably be Nitella opaca or N. fexilis. The bottom of the northern pools are too muddy or are too much disturbed by cattle and domestic poultry to yield any interesting species, but in these comparatively undisturbed waters the very small and local plants Elatine hexandra or E. Hydropiper may occasionally be met with, or certainly a profuse growth of the shoreweed (Littorella), or perhaps the pillwort (Pilularia globuliferd] . Instead of the ferns the Ceterach or Asplenium Tricbomanes, we shall meet with Blecbnum and Dryopteris montana (Lastrea oreopteris) or perhaps Osmunda. But space prevents one extending these com- parisons, interesting and suggestive as the subject may be. The following species have as yet been found on no other of the formations : Illecebrum verticillatum, which was discovered by my young friend Mr. Fisher, and known elsewhere in Great Britain only from Devon and Cornwall ; the winter green (Pyrola minor] ; the beech fern (Pbegopteris polypodioides], found by my lamented friend Mr. F. Tufnell ; the marsh cinquefoil (Potentilla palustris) ; the marsh gentian (Gentiana Pneumonanthe) ; the swine's succory (Amoseris pusilla] ; the pillwort (Pilu- laria} ; the climbing fumitory (Capnoides [Coryda/is] claviculata] ; the club moss (Lycopodium inundatum) ; and the grass Agrostis setacea. The enumeration of the stratified rocks of Berkshire may be con- sidered to come to an end with the Bagshot Beds, using that term in a i 49 7