296 BRITISH PLANTS 



officinalis (melilot), Ononis arvensis (rest-harrow), Filago 

 germanica (upright cudweed), Matricaria inodora (scent- 

 less may-weed), Bartsia Odontites (hemi-parasitic on 

 grasses), Malva rotundifoUa (dwarf mallow), Potentilla 

 reptans (creeping cuiquefoU), Polygonum aviculare (knot- 

 grass), many species of Chenopodium (goosefoot). 



Commons. — In many parts of the country, within the 

 region of cultivation, large stretches of waste land exist, 

 on which the dominant plants are bracken, furze, and 

 bramble. The soil is always very poor and dry, either 

 sandy or stony. In many cases these commons are relics 

 of cultivation. They are usually situated near towns, 

 where land is valuable, and where every part of it is as 

 far as possible utilized for raising crops, or used as pasture- 

 land. Woods on dry soils have been destroyed, and the 

 land experimented with in this way, but it has often 

 turned out unprofitable, and the land has been allowed 

 to go to waste. Rough grasses and herbs are the first to 

 obtain a hold on the soil, and then larger plants, including 

 the three which are now dominant. The association is a 

 very mixed one, and of an open character. Birches, and 

 often oaks, are more or less abundant, and it seems prob- 

 able that in the course of time a Birch-Oakwood associa- 

 tion wUl once more occupy the soil (see p. 271). 



The most abundant plants growing with the three 

 dominant ones are dry-loving grasses — e.g., Festuca ovina, 

 Aira flexuosa, Aira prcecox, Brachypodium pinnatum, 

 Nardus stricta, and Agrostis vulgaris. Calluna vulgaris 

 and Erica cinerea are often abundant, and many typical 

 heath -plants — e.g., Thymus Serpyllum, Euphrasia offici- 

 nalis, Lotus corniculatus, Hypericum pulchrum, Galium 

 saxatile, Teucrium Scorodonia, Potentilla Tormentilla, 

 P. reptans, Hieracium Pilosella, Rumex Acetosella, Veronica 

 officinalis. Campanula rotundifoUa, Stellaria graminea, 

 Erodium cicutarium, Viola sylvatica, etc. Of woody 

 plants other than those mentioned, the hawthorn, broom, 

 and sloe are the most common. 



Many of the wider strips of roadside-waste are of this 

 character. 



Cultivated Ground. — ^Where the land is periodically 

 ploughed to receive new crops, weeds are very abundant. 

 When the crop is in its seedling-stage, and earlier, the 

 weeds have nothing to compete with, and can grow apace. 



