FERN ALLIES OP NEW ZEALAND. 11 



CHAPTER II. 



NOMENCLATUEE AND PEINCIPLES OF CLASSIFICATION. 



All plants, when scientifically described, have two names given to 

 them ; the first of these is the generic name, or that of the genus to 

 which the plant belongs ; the second is the si^ecijic name, or that of 

 the particular species of plant. This binomial nomenclature — or 

 giving of double names to plants — was one of the many revolutionary 

 changes in the march of scientific progress which we owe to the 

 celebrated Swedish naturalist Linnseus. 



The generic names (of ferns at any rate) are usually derived from 

 the Greek ; and, in giving such names, botanists have often been 

 guided by very fanciful considerations. The name most commonly 

 used among the genera of ferns is Pteris (Gr. pteron, a wing), origin- 

 ally given by Linnaeus to the common Bracken. This being one of 

 the commonest of ferns, the name has come to be used very 

 frequently as synonymous with the name fern. Besides the genus. 

 Pteris itself, we have, however, only one New Zealand genus into 

 whose name this term enters, viz., Gystopteris or Bladder-ferns. 



The specific name is commonly of Latin origin, and is often 

 expressive of some characteristic feature of the plant (e.g., hirsutum), 

 or of its habit (scandens), or of the locality where it occurs (tun- 

 bridgense), or it may be given in honour of some botanist or collector 

 — usually the first discoverer of the plant {cunninghamii). It is usual 

 to commence the generic name with a capital letter, and the specific 

 name with a small letter, even when it is derived from a proper 

 name. 



Frequently the same fern has been found in different countries, 

 and named by different botanists, whose descriptions may have been 

 published in any one of the numerous British or foreign publications 

 brought out so abundantly during late years ; and thus it comes to 

 have two or more names. Or the same botanist may have obtained 

 two or three varying forms of the same plant ; these he describes 

 under different names as being distinct species, and then someone 



