1 82 WEEDS OF FARM LAND 



which grow in a particular way and give rise to the character- 

 istic appearance. The fungus consists essentially of long 

 white threads or hyphae, forming a mycelium which ramifies 

 and spreads through the soil. At intervals this mycelium 

 throws up fructifications popularly known as toadstools or 

 puffballs. Frequently these toadstools are fairly slight and of 

 a medium size, 2-4 inches across, but occasionally they are 

 very large and solid, measuring from 8-IO inches in diameter. 

 The particular fungi which form the ring begin to grow 

 from a central point and branch outwards in all directions, the 

 fructifications being thrown up year after year on the outer 

 edge of the ring, which grows bigger annually. The area 

 occupied by the ring the previous year seems to be particularly 

 well manured by the fungus, as the grass thereon grows 

 luxuriantly and is always very dark in colour. The affected 

 areas are marked out by their luxuriant growth and dark 

 colour, even in mowing fields in which the grass is knee deep. 

 In pastures the grass of the rings is much appreciated by 

 stock which keep it very closely cropped, but still the dark 

 colour is evident. After one year of heavy growth the transient 

 stimulus is apparently exhausted and the herbage falls behind 

 that of the rest of the field, indicating that the ground has 

 been seriously impoverished. The personnel of the herbage 

 also changes. There is no fixed scheme of colonisation, but in 

 each field the growth within and without the ring shows dis- 

 tinctive differences. Sometimes yarrow (Achillea millefolium) 

 and ribgrass (Plantago lanceolatd] appear among the thick 

 grass of the ring, though they are absent elsewhere ; some- 

 times cocksfoot is the chief grass associated with a good deal 

 of hogweed. Another rather usual combination is field brome 

 and rough meadow-grass, frequently combined with sorrel 

 and cocksfoot. One very perfect example seen at Wickwar 

 (Glos) consisted chiefly of ryegrass and cocksfoot. Within 

 the ring the herbage was shorter and showed a mixture of 

 grasses and weeds that indicated poverty of soil. It included 

 vernal-grass {Anthoxanthum odoratum), rough meadow-grass, 

 dog's tail, very little cocksfoot and an abundance of weeds. 



Too many fairy rings are not desirable in grass-land, but 

 unless they are so abundant as to threaten the herbage 

 seriously it hardly pays to attempt to eradicate them. Liberal 

 manuring will do much towards getting rid of them, but 

 definite efforts at eradication are better reserved for lawns and 

 special pieces of grass-land. 



