334 24. ROSACEiS. 



Analogy suggests a question, whether the true and only 

 original stock of the arborescent Cherries, of the gardens 

 and of the wilds, is not really the fruticose P. Cerasus ? 

 There is a very austere and fruticose wild Sloe (P. spinosa) 

 which is almost admitted to be the origin of all the Plums 

 (P. insititia and P. domestica) . And there is a very aus- 

 tere and fruticose wild Crab, with small romid fruit, which 

 appears to be the genuine stock of the arborescent Apples 

 of the gardens, and of all those intermediates which are 

 now found in our hedges and copses ; some, as deterio- 

 rating varieties, immediately derived from the garden trees ; 

 some, probably, as improving varieties, originating from 

 the true wild stock. At any rate, some of the garden 

 Cherry-trees have botanical characters inteimecUate be- 

 tween those assigned, by authors on Botany, to P. Cerasus 

 and to P. avium, respectively. 



317. Spir^a Ulmaria, Linn. 



Area, general. 



South limit in Cornwall, Isle of Wight, Kent. 



North limit in Shetland, Orkney, Hebrides. 



Estimate of provinces 18. Estimate of counties 82. 



Latitude 50 — 61. British type of distribution. 



A. A. regions. Inferagi'arian — Midarctic zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 850 or 900 yards, in the East Highlands. 



Range of mean annual temperature 51 — 38. 



Native. Pratal and Paludal. A common or frequent 

 plant throughout Britain ; ascending to the rocks of Can- 

 lochen Glen, and probably to 800 yards on the mountams 

 by Loch Erricht, at_the head of Moray. 



