INTRODUCTORY EXPLANATIONS. 45 



a very scanty flora. The species which are thus charac- 

 terized by their general presence and prevalence, or rare 

 only in those tracts which are seldom visited by botanists, 

 become famiharly known and contemned under the desig- 

 nation of " common things ;" and being much neglected, 

 in consequence, it has often been found difficult to ascer- 

 tain their true distribution and comparative frequency, on 

 recorded evidence. It is to be observed, that the name 

 of ' British type ' is applied to them, not on any hypothe- 

 tical notions of their origin within Britain, but because 

 such a general distribution and prevalence indicates great 

 adaptation to the climate and other local conditions of 

 this country, and entitles them to be considered thorough- 

 ly native both in England and Scotland — to be Britons in 

 the fullest signification of the term. It is probable that 

 about two-fifths of the whole number of British species 

 (including ' natives,' ' denizens,' ' colonists,' as presently 

 to be explained) will be referred to this, the most general 

 type of distribution ; although, at present, the number 

 cannot be exactly stated. Among the more thorough 

 examples of the type may be instanced the following, 

 namely, Alnus glutinosa, Betula alba, Corylus Avellana, 

 Salix caprgea, Rosa canina, Lonicera Periclymenum, He- 

 dera Helix, Cytisus scoparius, Calluna vulgaris. Ranun- 

 culus acris, Cerastium viscosum, Potentilla Tormentilla, 

 Trifolium repens, Stellaria media, Lotus corniculatus, Bel- 

 lis perennis, Senecio vulgaris, Carduus palustris. Taraxa- 

 cum officinale, Myosotis arvensis. Prunella vulgaris, Plan- 

 tago lanceolata, Polygonum aviculare, Urtica dioica, 

 Potamogeton natans, Lemna minor, Juncus eflfusus, Carex 

 panicea, Poa annua, Festuca ovina, Anthoxanthura odora- 

 tum, Pteris aquilina, Polypodium vulgare, Lastraea Filix- 

 raas. 



