IV PREFACE. 



I was first prompted to the undertaking by the inconvenience 

 that I have frequently experienced in the nomenclature of our 

 Plants, as arranged in the various Catalogues, the Authors of 

 which have generally left their names unaccompanied with any 

 discriminative remarks relative to their most essential generic and 

 specific characters, which might enable us, in some degree, to 

 ascertain their identity. Much merit is undoubtedly due to the 

 late Mr. Donn, for his excellent arrangement of the Plants in the 

 " Hortus Cantabrigiensis" which contains much useful informa- 

 tion in a small compass, and has established a basis for the 

 nomenclature that is most practicable for general utility. In 

 " Sweet's Hortus Britannicus" we have an extensive collection 

 of Plants, arranged with the colour of flower of each species, 

 and references to the Botanical Works in which they are figured 

 or described, &c, which tend considerably to enhance its value. 

 We have, again, in " Loudon's Hortus Britannicus" much valu- 

 able information conveyed to us within a limited space ; much of 

 which is, by ingenious signs, adapted by that indefatigable Au- 

 thor for indication of the different habits of the Plants. But 

 the above-mentioned Catalogues are all deficient, in not giving 

 the generic and specific characters, which are essential for discrimi- 

 nating one plant from another. 



There are, unquestionably, many other elementary Works 

 that contain numerous illustrations and details on the natural 

 affinities of Plants ; but these books are generally confined to 

 the hands of the few, and scarcely within the reach of the opera- 

 tive Gardener ; they are, moreover, chiefly confined to particular 

 branches of the science ; and no individual work that has yet 

 appeared, to my knowledge, combines within itself, in my estima- 



