IMPROVEMENT OF GRASS LAND 151 



Certain weeds have already been specified (p. 27) 

 as indicative of damp soils, and where such weeds are 

 prevalent it will often be found that draining is neces- 

 sary before they can be eliminated. On damp, low- 

 lying pastures and meadows draining is almost certain 

 to effect an improvement in the herbage, especially in 

 conjunction with liming and judicious manuring. 



Another matter to which attention may be directed 

 at this point is that many weeds are practically in- 

 tolerant of lime, which may therefore be effectively 

 used against them. Among such weeds may be men- 

 tioned Sheep's Sorrel (Rumex Acetosella), Common Sorrel 

 (R. Acelosa), Spurrey (Spergula arvensis), Corn Marigold 

 (Chrysanthemum segetum), Bracken or " Fern " (Pteris 

 aquilind), Heaths and Ling (Erica sp. and Calluna 

 vulgaris), and Foxglove (Digitalis purpured). Liming is 

 also useful in reducing Mosses, Bent Grasses (Agrostis 

 sp.), Yorkshire Fog (Holcus lanatus), and Wavy Hair 

 Grass (Air a flexuosd). 



The weeds of grass land are dealt with individually 

 below. 



It may be noted at the outset that the Natural Orders 

 contributing the largest numbers of weeds are the 

 Ranunculacece, Cruciferce, Caryophyllacece, Rosacece, Umbel- 

 liferce, and Composite, the last named being especially 

 prolific in weeds of a harmful character. It is con- 

 venient to deal with the weeds under their Natural 

 Orders : the latter are taken consecutively. 



RANUNCULACE.E 



Traveller's Joy (Clematis Vitalba L.). This well-known 

 climbing plant is commonly termed Old Man's Beard, 

 from the tufted feathery appearance of the fruiting 

 stage ; it can only be included as a weed because of 



