BOTANY 



with the crimson blossoms of the hard-head (Centaurea nlgra] as the 

 variety decipiens, and there is abundance of the purple flowered autumnal 

 felwort (Gentiana Amarella), and in a few places the much larger 

 blossomed Gentiana germanica. Three or four species of the eye-bright 

 Eupbrasia occur, including nemorosa, curta, Kerneri and graci/is, but some 

 of these grow where there is a thin coating of loamy soil or possibly 

 brick-earth. 



In the deep combe above the Kembles and Ellesborough there are 

 great bushes of the box (Buxus sempervirens) , and it may be native in 

 the county here and on the downs above Edlesborough. At Elles- 

 borough it affords shelter for a great number of rabbits, and about their 

 warrens the henbane (Hyoscyamus niger) is abundant, and growing upon 

 the earth thrown out by them one of the earliest plants to appear is the 

 sandwort (Arenaria leptoclados). The tower cress (Arabis hirsuta] is found 

 plentifully in a few situations, but is most abundant in shade, which is 

 rather unusual for this species. Nor do the arable fields lack their com- 

 plement of interesting plants, and the white mustard and candy-tuft have 

 been already mentioned, but there are also the fumitories Fumaria densi- 

 flora, F. Vaillantii and F. parviflora, the toadflax (Linaria viscida), the 

 sainfoin (Onobrycbis "viciteformis) , but the special treasure is a very local 

 species which has its extreme western range in the county, namely the 

 great pig-nut (Carum Bulbocastanum) , which also occurs in Cambridge- 

 shire and Herts, but does not appear to extend west of Ivinghoe. The 

 large tuberous root is greedily eaten by pigs. About Halton and Tring 

 there is the poisonous deadly nightshade (Atropa Belladonna) , the spurge 

 laurel (Daphne Laureo/a), the very local bedstraws Galium syhestre and 

 G. erectum, the meadow clary (Safoia pratensis), and the field mouse-ear 

 (Cerastium arvense) ; Vicia syhatica, Polygonatum multiflorum and Pyrola 

 minor. 



The Chalk is occasionally covered with leaf-mould and with loam, 

 or brick-earth, and when the calcareous character of the soil is more 

 or less masked a corresponding change in the flora takes place ; patches 

 of the ling (Calluna Erica), of the louse- wort (Pedicularis syhatica) and 

 other ericetal plants occur, but as these are not normal constituents of a 

 cretaceous flora they will be referred to subsequently. There are three 

 large dips in the Chiltern escarpment : one near Princes Risborough, 

 another near Wendover, and a third which lies between Tring and 

 Aldbury. The neighbouring hills such as Beacon Hill near Wendover 

 and those above Ivinghoe and Halton give very beautiful and extensive 

 views over the vale to the distant hills of Northants and Wilts. The 

 chalk rock of the Lower Chalk is also to be seen inland at Chesham, 

 High Wycombe, as well as in several places overlooking the Thames 

 between Henley and Marlow. 



THE UPPER CHALK WITH FLINTS is about 300 feet thick, and forms 

 the eastern slope of the Chiltern Hills. This chalk is largely burned for 

 lime. Although there is a considerable portion of the chalk area where 

 the Upper Chalk forms the subsoil and gives a home for calcareous loving 



37 



