BOTANY 
butterfly (H. ch/oroleuca), and the helleborines Epipactis latifolia and E. 
violacea are not infrequent in the northern division, owing apparently to 
the calcareous nature of the subsoil in many parts. Among plants which 
seem to occur only on the Chalk are the pasque flower (Anemone Pulsa- 
ti/la), which flourishes on the slopes of the chalk combes near Barton, 
the blue milk vetch (Astragalus danicus), the horse-shoe vetch (Hippo- 
crepis comosa), the squinancy wort (4sperula cynanchica), the field rag- 
wort (Senecio campestris), the mountain cat’s-foot (Antennaria dioica), the 
Canterbury bell (Campanula glomerata), the felwort (Gentiana Amarella), 
and the ground pine (Ajuga Chamepitys). In the list of chalk-favouring 
plants there are possibly others that are practically limited to the Chalk. 
The Lower Greensand is responsible for several plants which in its 
absence would be rare or non-existent in the county. It is a warm 
and greedy soil, which in parts will grow little more than pines and 
larches, but where it is mixed with clay a very productive loam is 
formed, well adapted for market-gardening, as at Biggleswade, Sandy 
and Potton. The phosphatic nodules known as coprolites are found at the 
base of the Greensand at Sandy, Shillington, Sutton, Potton and Ampt- 
hill. Two other seams of coprolites occur in the Gault near Barton, 
but as they are usually found at some depth it would be difficult to say 
how far the coprolites affect the character of the flora. Among the plants 
which have been found only on the Greensand are the silver cinquefoil 
(Potentilla argentea), the saw-wort (Serratula tinctoria), the sheep’s scabious 
(‘fastone montana), the bilberry (Vaccinium Myrtillus), and the lily of the 
valley (Convallaria majalis). In the list there are several others that pre- 
fer the Greensand, and possibly some of them are limited to it. The 
grasses Aira precox and A. caryophyllea occur not only on the Greensand, 
but also on a patch of Tertiary sand in the south of the county. 
The river Ouse at Bedford is about go feet above sea-level. Luton 
rises from 350 to 450 feet, Dunstable to 483 feet, and Dunstable downs 
to 799 feet. The northern part of the county is hilly, though the heights 
rarely exceed 300 feet. In the centre and on the eastern side the county 
is flat right away into Cambridgeshire, but it can hardly be described as 
fen country. 
For the last hundred years, especially, the county has been under 
very high cultivation, particularly in the market-gardening districts. 
The most interesting piece of marshland is undoubtedly Flitwick Moor, 
which is a peat bog on Greensand, associated with the river Flitt, and 
containing a chalybeate water derived from the ferruginous subsoil in 
contact with vegetable acids. At Gravenhurst there was formerly an 
interesting moor where such plants as the marsh arrow-grass (Triglochin 
palustre) and the marsh helleborine (Epipactis palustris) grew. Mr. C. 
Crouch reports that the former is still found on what survives of the 
moor, though the orchid is apparently extinct in the county ; and 
in referring to such plants as the flea sedge (Carex pulicaris), the 
butterwort (Pinguicula vulgaris), and the grass of Parnassus (Parnassia 
palustris), which he found on the dry chalk of the Markham Hills, he 
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