Extirpation of Weeds. 241 



plentiful produce of seeds, which will lay in the ground many years, ready to vege- 

 tate next time the land is pulverised early in the spring ; this should, therefore, be 

 done in the fallow, which would occasion the seeds to vegetate, and the plant might 

 be destroyed by ploughing under before its seeds ripen. 



2. Lambs lettuce, corn salad (Valeriana locusta). This plant I never observed 

 till last summer, when I certainly believe it was more plentiful than common in 

 this neighbourhood. I observed it on my farm, both in corn fields and arable 

 pastures, but not in such quantity as to be injurious. In a hard tilled field near 

 Lichfield, I found it in great abundance ; it is an annual plant, not at all for- 

 midable as a weed ; it is eaten as a salad, and by cattle ; for the former purpose 

 little inferior to young lettuce. See Withering, and Flora Rusiica, 



3. Dogs grass — Triticum repens. 



4. Bent grasses — Agrostis' alba and stolonifera, 



5. Tall oat grass — Avena elatior. 



6. Creeping soft grass — Holcus mollis. 



The roots of those, and perhaps of some other of the hardy perennial grasses, 

 compose what the farmers call quick, couch, or squitch, that plague and curse to 

 arable cultivation ; they are sometimes so interwoven together in the soil, in land 

 that has been under hard tillage and bad management, as to form a perfect matting 

 and to choke the plough : they abound most in light and mixed soils, not equally 

 infesting strong clays : the first of these, the dogs grass, has been generally referred 

 to by writers, as alone producing couch or squitch, but this idea is now generally 

 known to be erroneous ; this grass principally abounding in hedges and gardens, 

 though sometimes plentiful in arable fields, yet not one-tenth part of the squitch of 

 arable land is produced by this grass. The most general arable land squitch grass 

 is of the Agrostis family, but to which particular species that most complained of 

 by farmers belongs, is not yet agreed amongst botanists. Dr. Stokes refers it to 

 the fine htm ( Agrostis capilarisj ; Mr. Dickenson assures me it is a variety of 

 the Agrostis alba ; but Mr. Curtis informed me, in London, that this squitch 

 grass has never yet been rightly specified, that it ought to be termed Agrostis 

 repens. I have frequently observed the ear or awn of this grass to have the 

 general habit of the Agrostis, and it is very probable that more species than 

 one of this genera have the habit of running in the roots, and producing couch or 

 squitch. 



VOL, V. I i 



