BOTANY 



must in the great majority of cases have been the means of introducing 

 it to numerous isolated pieces of water. 



Spores of ferns are also carried by water, for I have seen seedling 

 species of the bracken (Pteris aquilirm) which have been brought down 

 from Harleston, growing on the flood-mark on the brick walls of wharves 

 in the southern part of Northampton. The sweet flag [Acorus Calamus) 

 has spread by the agency of streams along the larger rivers of eastern and 

 southern England, but in this instance it is to portions of the creeping 

 rhizome being carried down by the stream to some other anchorage, that 

 its dispersal over a wide area is probably due. It occurs by the Ouse at 

 Stony Stratford on both sides of the stream, and has the appearance of 

 being native. The yellow monkey flower {Mimulus Langsdorffii) so fre- 

 quent in some of the Buckinghamshire streams, does not yet appear to 

 be established with us. 



THE BOTANICAL DISTRICTS 



Following the example which has been set by the large proportion of modern local floras, 

 I have based the divisions of the county for botanical purposes upon the river drainage, and by 

 doing so have brought the flora of Northamptonshire into harmony with that of the neigh- 

 bouring counties in which a similar plan has been adopted. Those botanists who are 

 interested in plant distribution through the smaller river districts of England, may thus have 

 less trouble in tracing the constituents of each river-flora than would be the case if an artificial 

 or geological basis of division had been followed. Unlike some counties, such as Berkshire, 

 which happen to be wholly in the drainage basin of one large river, Northamptonshire has a 

 more composite system. Owing to the great length of the county, which from Crowland to 

 Aynhoe is seventy miles, and from its ranges of hills, it has been the boast of the county that 

 we send streams to all the neighbouring counties but receive none in return, and we have the 

 water-parting of three different and important river systems all starting within our area, the 

 outlets of which into the sea are very widely separated. They are the Severn, the Thames, 

 and the Ouse. The first is represented by two streams, the Learn and the Avon, which are 

 separate and distinct in our county, but unite in Warwickshire, while the united stream, still 

 bearing the classic name of Avon, itself unites near Tewkesbury with the Severn, whose outfall 

 is into the Bristol Channel. The second consists of the Cherwell, and is an important feeder of 

 the Thames, which falls into the North Sea near the English Channel. The third, the Ouse, 

 which in our area is drained by the Ouse, the Nene and the Welland, each distinct streams, and 

 flowing into the Wash in the German Ocean by different outlets. As the portion of our 

 county drained by the Ouse is large I have thought it well to separate it into five subdivisions. 



The r.ames and limitations therefore of the seven botanical districts are as follows : — 



1. The Avon or Leam 

 This district occupies a narrow strip on the north-western side of the county, and is 

 bordered by the counties of Leicester and Warwick, and corresponds with District 2 of the 

 Flora of Leicestershire, znd with Districts 4 and 5 of Bagnall's F/ora of JFarwickshire, where the 

 drainage of these two streams forms two districts. It may be well hereafter when the know- 

 ledge of the flora of this part is more complete than it is at present to follow Mr. Bagnall's 

 plan of keeping the two river drainages separate. The boundary of the Avon district, from 

 the district of the Cherwell, Nene, and Welland is as follows ; but it must be borne in mind 

 that in some cases, from various causes, the boundary is not precise. From the Warwickshire 

 border near Marston Hill, the turnpike road from Priors Marston to Charwelton is followed. 

 Then the boundary line is carried northwards to Arbury Hill (734 feet), capped with North- 

 ampton sands, which forms the culminating point of the county, and which is therefore in two 

 different drainage systems. From Arbury the high ground to Staverton marks the limit, and 

 from Staverton the turnpike road, the highest point of which is 590 feet, to Daventry forms 

 the boundary as far as to Drayton Lodge, then the line is traced across country by Drayton 

 Grange to Ashby Grange, leaving Drayton reservoir (in the Nene district) on the east, and 

 Bragbrough House on the west. At this point the turnpike road to Barby marks the boundary 



57 



