A HISTORY OF DEVONSHIRE 



Nearly the whole of the district belongs to the Carboniferous system, and a large propor- 

 tion of the land is poor in quality. There is a patch of New Red Sandstone about the town 

 of Hatherleigh, and a larger patch about a mile broad more or less stretching from Jacobstowe 

 village to Exbourne and Sampford Courtenay villages and further eastwards. 



There is a small patch of Greenstone about a mile south-west of Hatherleigh town ; 

 across Okehampton Park are some bands of Greenstone and a small patch of Limestone. In 

 a quarry near Furzehill, not far from Hatherleigh, two Elvan bosses come up along the 

 bedding planes of the Culm Measures and terminate abruptly at some feet from the surface 

 (W. A. E. Ussher). The southern part of Okehampton Hamlets penetrates about 3 miles 

 into Dartmoor and is granite. 



The climate of the district is illustrated by the following tables, which have been obtained 

 in the way explained under the Barnstaple district : — 



Table i. — Decade 1890-9 



Station 



Altitude, 

 feet 



Mean annual rainfall. 

 Inches 



Mean annual No. of days 



on which 'oi in, or 



more of rain fell 



Petrockstow 



Okehampton 



521 



38-45 

 45-54 



189 



Table 2 





Altitude, 

 feet 



Mean annual rainfall, 

 inches 



Temperature in Fahrenheit degrees 





Mean minimum 



Mean maximum 



Alverdiscott .... 

 Great Torrington . . 

 St. Giles in the Wood . 

 Okehampton .... 



330 

 336 

 420 

 521 



4473 

 49-26 



19-25 

 22-5 



i8-8 



8575 

 85 

 84-8 • 



A rare form of water-crowfoot {Ranunculus tripartitus = R. intermedius) occurs in the 

 moorlands of the district ; south of Okehampton, according to Mr. Moyle Rogers, it grows 

 usually on mud or in very shallow water, with its petals frequently 5 -veined and as large as 

 those of R. hnormandi, in company with which it is often found. The common scurvy grass 

 [Cochlearia officinalis var. littoralis) grows near Holsworthy about 9 miles from the sea ; the 

 same botanist observes that the occurrence of this maritime plant in several inland places in 

 this district (and a like observation applies to the Barnstaple district) points to its former cultiva- 

 tion in the neighbourhood. The mountain or English stonecrop {Sedum anglicum) is plentiful 

 in rocky, stony and gravelly places, and is prevalent in the granite area ; it was recorded for 

 such stations in the county by Hudson in 1778. The milk-thistle [Silybum marianum) has 

 long been established at the base of the common at Great Torrington. The marsh gentian 

 {Microcala filiformis) was discovered in Clawton parish ii September 1883, by Mr. Archer 

 Briggs and recorded in the Journal of Botany, xxi. 316 in the same year ; it had been 

 reported for the county, but without precise locality, by Hudson, in 1778. The stalked 

 speedwell {Veronica montana) is fairly frequent in the hilly woods and thickets of the district ; 

 it was mentioned in 1797 by Polwhele on the authority of Dr. Wavell as a rare plant 

 growing in a lane near Torrington leading towards Holsworthy. Red mint {Mentha sativa, 

 sub-sp. M. gentilis) was reported from Winscott in Peters Marland by Polwhele in 1797. 

 The Devonshire or Dutch myrtle {Myrica Gale) has been found in good quantity by Mr. 

 Moyle Rogers in Upper Bridgerule bog. 



^ercus Rohur. — ' On an estate of Dennis Rolle, Esq., near Great Torrington, an oak 

 tree was cut through about 1776, the body of which measured thirteen feet six inches 

 diameter ; and on the plane of the section two couples danced a country dance. . . In 

 Okehampton Park is an oak which deserves attention for its girth and spread ' (Polwhele in 

 ^797)- The haretail rush {Eriophorum vaginatum) is not uncommon in bogs on high moors; 

 Polwhele recorded it near the road leading from Clovelly to Kilkhampton. The wood 

 melic-grass {Melica nutans) was recorded by Polwhele in 1797 on the authority of Dr. 

 Wavell as occurring in a wood near Dolton ; this record has been doubted. Keys in 

 his Flora of Devon and Cornwall wrote : ' As no later botanist has found it, it is scarcely 

 worth while to insert it here. It is marked with an " o " for Devon in Cyb. Brit.' The 

 difBculty of accepting it is increased when it is remembered that Linnaeus included both 



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