39 



THE ROCK-SOIL METHOD AND BALLOTA 

 NIGRA LINN. IN LINCOLNSHIRE. 



Rev. E. ADRIAN WOODRUFFE-PEACOCK, F.L.S., F.G.S., Etc. 



The single sheet, 3 by 3.75 inches, mode of collecting notes on 

 every circumstance of plant growth, I named the Rock-Soil 

 Method, in honour of Mr. Clement Reid for his book on " The 

 Origin of the British Flora.' He practically deals with quater- 

 nary rock-soils of various ages in the same way that I work them 

 when they have been exposed by elevation and modified again 

 by denudation and plant growth. 



As a typical instance of a rather difficult species to analyse, 

 let us take Ballota nigra. It is pre-glacial at Pakefield * 

 but rare. It was recorded for Lincolnshire by Rev. J. Dods- 

 worth in 1836, Sir Charles Anderson in 1847, and H. C. Watson 

 in 1 85 1 ; and many times since. It is found in all our eighteen 

 natural history divisions. 



The following is its Rock-soil range, as far as it has yet been 

 worked out on some 150 sheets : — 



1. Blown Sand 9 



2. Carstone i 



3. Chalky Boulder Clay . . 12 



4. Cornbrash 4 



5. Estuarine Alluvium . . . . 9 



6. Fen Gravel 6 



7. Freshwater Alluvium . . i 



8. Hessle Boulder Clay . . i 



9. Hibaldstow Limestone . . 8 



10. Kimeridge Clay . . . . 2 



11. Kirton Limestone . . . . 2 



12. Lincolnshire Limestone . . 10 



13. Lower Chalk i 



14. Lower Lias Clay . . . . 3 



15. Marine Sand 3 



16. Marlstone i 



17. Old River Gravel . . . . 3 



18. Oxford Clay 4 



19. Peat (Cultivated) . . . . 2 



20. Purple Boulder Clay . . 4 



21. River Gravel 5 



22. Sandy Glacial Gravel . . 39 



23. Spilsby Sandstone . . . . 7 



24. Tealby Clay i 



25. Upper Chalk 2 



26. Very Chalky Boulder Clay i 



It has been found fiore alho on Fen Gravel, Peat, River 

 Gravel, Sandy Glacial Gravel, Lincolnshire Limestone, and 

 Spilsby Sandstone. In the form foliis variegatis on Hibaldstow 

 and Kirton Limestone. Its flowering -f range extends from 

 May 30th to November 25th. 



It is plain at once that Ballota is a lover of warm, open, 

 and limy soils. When the sheets of notes are analysed, the 

 following points come out. It is a hedge and ditch side species, 

 but it seems to prefer a bank to the flat in the proportion of 



* Journal Linnean Society, 1908, p. 218. 



* By ' flowering- ' I mean when the stamens are shedding- active pollen. 



1909 February i. 



