NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 667 



horsetail. Of grass land weeds there are listed {Golchicum autum- 

 nale), buttercups, leguminous weeds, g'orse (Ulex) broom, rest har- 

 row {Ononis spinosa), dyer's green weed {Genista tinctoria), wild 

 carrot, burdock, knapweed {Gentaurea nigra), thistles {Girsiwm 

 arvense, C. acaule, G. Icmceolatum, G. palustris), cotton thistle 

 {Onopordum acanthium), daisy {Bellis perennis) , ox-eye daisy, rag- 

 wort {Senecio JMohaea) , plantains, yellow rattle, self -heal {Pru- 

 nella vulgwis), docks, sorrel {Bumex acetosa, B. acetosella), sting- 

 ing nettle {Urtica dioica) ; grasses: bent grass {Agrostis alba) tus- 

 sock grass {Aira caespitosa), Yorkshire fog {Holcus lanatus), 

 creeping soft grass {H. mollis), quaking grass {Briza media), bar- 

 ley grass {Hordeum, pratense), and the bracken {Pteris aqidUna), 

 horsetail, and mosses. 



Fig. 521. Common Porcupine or Needle Grass iSUpa spartea), A weed native 

 to gravel soil, soon succumbs to cropping, a,, single spikelet ; b, . fruit with 

 sharp pointed callus. 



(Lamson-Scribner, U. S. Dept. Agr. ) 



