PREFACE. 



When, in the autumn of 1842, I published my volume on the 

 Grasses of Scotland, I stated at one part of the preface, " My original 

 purpose was to embrace in this work all the Grasses of the United King- 

 dom, but the want of recent specimens of the Grasses peculiar to Eng- 

 land and to Ireland made it necessary that, for the present, I should 

 limit my plan. I propose, however, as soon as I have gained the pro- 

 per opportunities, to publish a similar account of those additional 

 species," Having taken pains since that time to procure those oppor- 

 tunities, I hasten to redeem my promise, by placing before the public 

 the completion of my original plan. 



The volume or part now published contains, on the plan followed 

 in " the Grasses of Scotland," a description of all the additional species 

 peculiar to England as well as to Ireland. 



Of a few of the species common to Scotland and to one or both of 

 the other great divisions of the United Kingdom, the descriptions have 

 been repeated ; and this has been done expressly as often as it appear- 

 ed that any thing had been omitted, or that any characters could be 

 added or amended, so as to render the distinction of closely allied spe- 

 cies more easy. For example, all the species and varieties of the genus 

 Bromus are described in this volume, or there is a repetition of the 

 descriptions of all the species met with in Scotland, and therefore given 

 formerly in the " Grasses of Scotland ;" for the species of this genus 

 are more numerous in England than in Scotland, and every botanist 

 will perceive at once a ready som'ce of the improvement of former 

 descriptions in the comparison of a greater number of species. 



