IV PEEFACB. 



has been laid down as a rule by some botanists, that no 

 plant can be a species whose distinctive characters are not 

 as manifest in an herbarium as when it is aUve. We are 

 told that our business -a^ descriptive botanists is not " to 

 determine what is a species," but simply to describe plants 

 so that they may be easily recognized from the dry speci- 

 men. The Author cannot agree to this rule. Although he, 

 in common with other naturalists, is unable to define what 

 is a species, he believes that species exist, and that they may 

 ofteii be ' easily distinguished aniohgst hvirig plants, even 

 when separated with difficulty when dried specimens only 

 are examined. He also thinks that it is our duty as 

 botanists to study the living plants whenever it is possible 

 to do'so, and to describe from them; to write for the use 

 and instruction of field- rather than cabinet-naturalists-— 

 for the advancement of a knowledge of the plants rathe:f 

 than for the convenience of possessors of herbaria, — alsd 

 that ' the differences which we are able to describe as dis- 

 tingilishing plants being taken from their more minute 

 organs is not a proof that they constitute only a single 

 species. It seems to be Our business to decide upon the 

 probable distinctness of plants before we attempt to define 

 them^^to make the species afford the character, not the 

 character form the species. 



This volume being intended as a field-book or travelling 

 conlpanion for botanists, it is advisable to restrict the space 

 allotted to each species as much as possible ; and accordingly 

 the characters and observations are only such as appear to 

 be necessary for an accurate discrimination of the plants. 

 Synonyms have been almost vehoUy omitted ; but when the 

 plant has not been represented in Syme's English Botany, 

 the plate of the original English Botany or some other 

 British plate is quoted. Localities are only given for new 

 or rare plants ; Mr. Watson's New Botanist's Guide and 



