BOTANY 



contrast : long stretches of bare down dotted over with junipers or sweet- 

 briar bushes, with here and there copses consisting to a considerable 

 extent of white beam-tree (Pyrus Aria) , guelder-rose (Viburnum Lantana), 

 dogwood (Cornus sanguinea), the abundance of various orchids and of 

 some grasses such as the oat-grasses (Ave na pubesc ens and A. pratensis), as 

 well as Bromus erectus, or the more sombre woods of yew (Taxus) and 

 locally of box (Buxus), all tend to give a character to this formation very 

 distinct from anything to be seen elsewhere in the county. Brewer 

 (Flora of Surrey, 1863) gives sixty species as peculiar to the chalk and 

 gault (including the Upper Greensand), some of which are now known 

 elsewhere. Among interesting plants not mentioned above are the two 

 milkworts (Polygala calcarea and P. amara), the horseshoe vetch (Hippo- 

 crepis comosa), everlasting pea (Lathyrus sy/vesfris), Lathyrus birsutus, 

 squinancywort (Asperula cynanchica) and bastard toadflax (Thesium humi- 

 fusuni) ; among still-surviving orchids, Cephalanthera enstfo/ia, Orchis 

 ustulata, the man orchis (Aceras anthropophora) , gnat orchis (Habenaria 

 conopsea), musk orchis (Herminium mon-orchis), the bee and fly orchids 

 (Ophrys apifera and O. muscifera), and the Turk's-cap lily (Lilium Mar- 

 tagori). The flora of the Bagshot Sands formation shows much similarity 

 to that of the Lower Greensand in its general and more striking features, 

 except in those parts where the bog myrtle (Myrica Gale] or Agrostis 

 setacea, two species which are peculiar to this formation, are plentiful. 

 The hills however are not nearly so high and the pine woods are less 

 extensive. Besides the above two species, the following are confined to 

 the Bagshot Sands : the great burnet (Sanguisorba qfficinatis), a bur-reed 

 (Sparganium affine], the bog-rush (Scbcenus nign'cans), slender cotton-grass 

 (Eriophorum gracile], Scirpus pauctflorus, and a sedge (Car ex dioica). I 

 find it difficult to characterize the London Clay by any special features : 

 in many it resembles the Wealden, and like that formation is very poor 

 in peculiar species. Fourteen are enumerated by Brewer, but nearly all 

 of these have either been found on other strata or are introductions like 

 the winter aconite (Eranthis byemalis) or blue anemone (Anemone apennina). 

 A species of hare's-ear (Bupleurum tenuissimum) is however peculiar to 

 the London Clay ; it is somewhat spasmodic in its appearance, but it 

 has been gathered in one or two places in recent years. With regard to 

 the Valley gravels which overlie the London Clay in many places ; the 

 Reading and Woolwich beds ; and the Thanet Sands, I have no special 

 observations, but according to Brewer the first-named possesses nineteen 

 peculiar species, most of which may now be passed over for the reasons 

 mentioned above ; there remain however a groundsel (Senecio viscosus), 

 goosefoot (Chenopodium glaucum), fritillary (Fritillaria meleagris) and squill 

 (Scilla autumnalis). For the Thanet Sands none are enumerated, while 

 for the Reading and Woolwich beds two are named ; of these there may 

 be mentioned Silene quinquevulnera now extinct, and there must be added 

 the sulphur clover (Trifolium ocbroleucum) . 



In the lists of rare or characteristic species appended to the accounts 

 of the separate districts but small notice has been taken of the very 



37 



