io6 Brenchley .-—The Weeds of Arable Land in 
An examination of the above analyses and of the available data 
shows : — 
1. Many of the differences between the two floras are simply differences 
in quantity, which change the balance of the distribution of the weeds on 
the different types of soil. 
2. Several plants which occur on various soils in Bedfordshire are 
definitely associated with chalk soils alone in the West Country. 
3. Other plants which are calcifuges in Bedfordshire are more or less 
frequently observed on chalk in the West. 
4. A few weeds are recorded from each district which are totally absent 
from the other. The number of such species, though, is far less than might 
have been expected, considering the distance between the two localities, 
involving some difference in clinfate and in soil. 
Points of Interest . 
1. While the association of particular weeds with certain soils is so 
well marked, the correlation between the weeds and the crops with which 
they occur is much less definite. The great majority of species occur 
indiscriminately with any kind of crop, whether cereals, roots, or ‘ seeds 
the nature of the soil being the determining factor of their occurrence. Still, 
a few plants do show some correlation with the crop, and to a large extent 
the West Country results tally with those of Bedfordshire in this respect. 
The ‘ seed ’ crops were chiefly clover, vetches, and a mixture of Italian rye- 
grass and clover. A very few species were almost entirely confined to such 
crops, but a larger variety of plants were noticeable on account of their 
rarity or absence among seeds. Also a very few plants were exclusively 
associated with cereals. 
Weeds only associated with cereal crops. 
Campanula hybrida Poa trivialis 
Lamium amplexicaule Potentilla reptans 
Lapsana communis Ranunculus arvensis 
Weeds only associated with seed crops. 
Arenaria serpyllifolia Geranium dissectum 
Cerastium vulgatum } , molle 
Geranium columbinum Sherardia arvensis 
Weeds absent or very 
Arrhenatherum avenaceum var. 
tuberosum 
Heracleum Sphondylium 
Lolium perenne 
Mentha arvensis 
rare in seed crops. 
Plantago media 
Poa annua (though once dominant 
among seeds) 
Triticum repens 
Veronica hederaefolia 
