.54 Mr. Winch on the Distribution of indigenous Plants. 



Limestone hill being only 632 feet above the level of the sea, little or no 

 difference can take place in the Flora, as far as elevation is concerned ; 

 but the arenaceous soil covering a space between Durham and Pittington, 

 and which arises from the disintegration of a bed of very friable Sand- 

 stone, intervening between the Limestone rocks and Coal measures, 

 certainly occasions a decrease of those vegetables peculiarly attached to 

 calcareous soils.* 



For a correct description of the New Red Sandstone district of the 

 county of Durham we are indebted to the researches of Mr. Hogg, in 

 the Essay previously noticed. The soil produced from the decomposi- 

 tion of its various strata covers the flat country bordering on the Tees, 

 from the sea shore to the West of Darlington, and in breadth, from North 

 to South, reaches from Stranton, in the neighbourhood of Hartlepool, to 

 the foot of the Cleveland Hills, in Yorkshire. Whether, owing to the 

 nature of the ground, many of its beds of Sandstone containing a consi- 

 derable portion of calcareous matter, or more probably from the warm 

 and sheltered situation of this South East corner of the county, we here 

 meet with several species of Plants, strangers to other less favoured 

 parts of the North ; these are, Bupleurum tenuissimum, Bupleuriim ro- 

 tundifoUum, Cuscuta Epithymum, Rumex Hydrolapatlium^ Butomus um- 

 hellatus, Cladium Mariscus, and Sagittaria sagittifolia. That their being 

 indigenous in this spot cannot be attributed, entirely to the nature of 

 the soil is evident, for the strata, which follow the course of the Tweed 



Coal found in its vicinity, but of Encrinal, Limestone, Grauwacke, Greenstone, Porphyry, 

 Hornblend Rock, Mica Slate, and Granite, the debris of distant mountains, situated far to 

 the West and North-West. 



* " Bromus pinnatus, Festuca pinnata of Smith's English Flora, is so characteristic of 

 the thin and Magnesian soils, that in some instances where the lower Sandstone is brought 

 by a fault to the exact level of the yellow Limestone (for example, on Bramham Moor,) 

 the demarcation may be traced, with great exactness, by the help of this plant, without the 

 assistance of a single excavation." — Sedgwick, in Geological Transactions, Second Series, 

 vol. iii. p. 42. 



I make no doubt that such is the case in Yorkshire and Nottinghamshire, but no botanist 

 has detected the Spiked Heath Fescue Grass in Durham or Northumberland, nor is it a 

 native of Scotland according to Hooker's Flora Scotica. This is remarkable, for the grass, 

 in question is rigid in habit, and has all the appearance of a hardy plant. 



