246 The Scottish Naturalist. 



appearances. Only a small proportion of the "casuals' 1 that 

 reward one's search seem at all able or likely to establish 

 themselves, and most of them die out in the course of a year or 

 two at most. 



It will be observed on a moderately careful scrutiny of the list 

 that the "casuals" fall naturally into a few great groups in 

 respect of their introduction into the district. These groups 

 are : — 



1. Trees or shrubs intentionally introduced into plantations. 



These species may not spread, or they may produce fruits, 

 which may be dispersed by the wind (poplars and willows), 

 or by birds (service-tree, &c.) 



2. Introduced with or as part of field crops — e.g., beans, tares, 



clovers, medick, grasses, &c. 



3. Introduced into gardens for their beauty, or for culinary value, 



and thence spreading by stolons or seeds, or thrown out 

 among weeds and rubbish of the garden. 



4. Accidental introductions, with imports — e.g., in wool, in Esparto 



grass, or other commercial products, or in ballast. Corn- 

 field weeds belong to this group. 



5. Mode of introduction doubtful, springing up sporadically. 



There are few in this group. 

 Specimens of all the following " casuals " from the north-east of 

 Scotland, except those quoted solely from " The Botanist's Guide," 

 are in the herbarium collected by myself. 

 Guide : Dickie's " Botanist's Guide " ; /. T. : Prof. James W. H. 



Trail; T.E.: Mr. Thomas Edwards, of Banff ; /. R. : Mr. 



John Roy. 



Ranunculace^e. 

 Ranunculus aconitifolius L. (flore pleno). Den of Craigston^ 



Turriff. 

 Eranthis hiemalis L. Alford on Donside (J. T.); in a 



plantation in the grounds of Duff House, Banff (T. E.). 



Introduced. 



* Helleborus foetidus L. Rubislaw Den, near Aberdeen (J. T.). 



Introduced. 



* H. viridis L. Recorded in Guide from Rubislaw Den. 



* Aquilegia vulgaris L. Along the Dee commonly, at Rubislaw,. 



and elsewhere. Escape. 



