INTEODUCTION. xU 



incomplete west European or Prencli flora. It is in tlie species 

 whicli it lacks ttat tte Irish, flora cMefly differs from the Englist ; 

 and the vast majority of the English plants which are ahsent from 

 Ireland axe common or widespread in western continental Europe. 

 Taking as standard the third edition of Hooker's Students Flora of 

 the British Isles, published in 1884, we find that, in round numbers, 

 1420 species and sub-species of Flowering Plants and Vascular 

 Cryptograms, either native or fully naturalized, occur m England 

 and "Wales, against 1000 in Ireland.* In making this comparison, 

 care has been taken to exclude with equal severity from the floras 

 of the two areas all introduced plants not fully naturalized, so that 

 the ratio of 70 to 100 may be taken as a fairly accurate expression 

 flf the relative richness of the two floras. It will be seen that the 

 comparison here made is one of Ireland with England- and Wales 

 only, so that the areas compared are less glaringly dissimilar in 

 «xtent and in range of latitude, and consequent range of climates, 

 than would be the case if the comparison were made with Great 

 Britain as a whole. The flora of Great Britain, on the standard 

 already mentioned, numbers 1480 species and sub-species, the ratio 

 of the total Irish flora to this being 67-5 to 100. 



British Type. — Almost all of the commonest indigenous plants 

 of England, the British Type species of "Watson, are found in Ireland, 

 where, as in England, they make up what may be called the ground- 

 work of the flora. Out of a total of 544 plants of this type found 

 in England and Wales, only the following eight species axe wanting 

 in Ireland : — 



British Type Plants absent from Ireland. 



Helianthemum vulgare. Chrysosplenium alterni- Paris quadrifolia. 

 Genista anglica. folium. Juncus oompressus. 



Potentilla verna. Erythrsea littoraKs. Avena pratensis. 



Unfflish and Germanic Types. — But when we come to the less 

 widespread groups or types in the English flora, such as the English 

 Type made up of plants which have their chief prevalence in England 

 and particularly in its more southern provinces, to the Oermamc, 

 Intermediate, Scottish, and Atlantic types which find their chief 

 development respectively in East England, in Middle Britain, in 

 'EoTih. Britain, and in West and South-west England, and to the 



* The Characea are excluded from both the English and Irish totals. 



