y 



92 1 RANUNCULACE^. 



Range of mean annual temperature 51 — 36. 



Native. Paludal. Distributed as generally, and almost 

 as plentifully, as the Ranunculus acris. But while the 

 Ranunculus rather decreases in abundance northwards and 

 upwards, the Caltha becomes less plentifiil towards the 

 drier lands and climate of the south or south-east of Eng- 

 land ; so that, to a Metropolitan botanist, the Caltha may 

 seem almost like a rare plant, when compared with the 

 Ranunculus. The south limit, doubtless, is in Cornwall, 

 though I find no record thereof. NB. High on the moun- 

 tains of Scotland, where the springs have a temperature of 

 38°, of Fahrenheit's scale, in July, the Caltha paJustris 

 becomes very dwarf and small-fiowered ; but it is there stiU 

 only a reduced fonn of the same species. Neither ought 

 the C. radicans, of Forster, to be looked upon as anything 

 else. About Castletown, in Braemar, in swampy places, 

 and especially in the drains cut across wet meadows in a 

 boggy soil/ I have seen plants with the stems flat to the 

 gi-ound, and rooting from their joints as they creep along 

 it ; the flowers much smaller than are seen in English 

 marshes, the petals being remarkably nan'owed, but not so 

 very small as those of the variety " minor" occasionally are ; 

 the leaves more triangular, and much more sharply seiTated, 

 than those represented for C. radicans, in English Botany, 

 2175. But I am fully satisfied that these differences, strong 

 as they appear in the extreme examples, are quite insuffi- 

 cient for specific diagnosis ; since they may be ti-aced, 

 degree by degree, in the most complete and satisfactory 

 manner, into the two commoner forms, the lowland and the 

 mountain fonns, or C. palustris and C. palustris rar: minor. 

 In the smnmer of 1844, 1 examined the plants extensively 

 and carefiflly, with a view to this question, almost daily du- 

 ring a sojourn of some weeks in Braemar and neighboiu"ing 

 places. Caltha radicans may be retained as a book species, 



