522 Dickie's Flora Aby'edonensis. 



upwards of fifty-one degrees. Here, however, our remarks will be confined to 

 the time of flowering, and a few examples from our registers will be given and 

 compared with those at other places. Times of flowering of 



Draba verna, 



Anemone nemorosa, 



Oxalis Acetosella, 



Ranunculus Ficaria, 



Tussilago Farfara, 



Viola canina, 



"From this it appears that, in general, our early spring plants are in flower 

 about one month sooner than at Upsal, and that the same species at Naples 

 are generally more than a month earlier than at Aberdeen. But the first date 

 of flowering of the same plants varies in this neighbourhood according as the 

 winter and spring months have been favourable or otherwise. Thus, in 1837, 

 Ranunculus Ficaria was first seen in flower on the 14th of February; and, in 

 the same locality (one well sheltered), in 1838, this species was first observed 

 in flower on March 26th, and this only in the neighbourhood of a copious 

 spring, whose temperature at the time of observation was about 44° F. This 

 difference in the date is accounted for, when we consider that, in 1837, the 

 mean temperatures of January and February were respectively 36*6° and 

 38-7°, and in 1838 they only reached 33*5° and 31- 1° respectively; and in the 

 latter year the ground was covered with snow from the 7th of January to the 

 first week of March.* The effect produced by the water of copious springs 

 is very striking: they retain in winter a higher temperature than that of the 

 air; and, consequently, plants growing under their influence are forced, and 

 become earlier than the same species growing in a less favourable locality. 

 On the 20th of April, 1837, Ranunculus hederaceus was first seen in flower 

 growing in water, whose temperature at the time was forty-two degrees (this 

 came from a neighbouring spring), while the mean temperature of the month 

 only reached 396° : in other localities this plant is much later. The facts now 

 mentioned are true regarding the spring and early summer plants. It has, 

 however, been stated, that the opposite effect is produced upon those which 

 naturally come into flower toward the end of summer or beginning of autumn; 

 because, as such make most progress during summer, and since springs are 

 colder in that season than the surrounding air, these plants will consequently 

 be retarded in their development. 



" The true character of a climate is much more faithfully indicated by the 

 natural products of the country, than by any instrumental observations what- 

 ever. The following foreign plants are said to bear exposure in the open air 

 during the whole year at Penzance, in Cornwall ; and those marked with an 



* We have observed the fact, that the nature of the previous winter and 

 spring exercises less influence over the time of flowering of those plants 

 which naturally appear in June and July than on those which flower in 

 March, April, and May. Thus, in 1836, Vicia sylvatica, Epilobium angusti- 

 folium, and Eupatorium cannabinum, were gathered near each other in full 

 flower on the 12th of July; and in 1837, about the same date, the two first 

 were in full flower, and the last was just beginning to show its flowers : the 

 mean temperature of the spring of the former year exceeded that of the latter 

 by 5°'5. These observations lead us to remark, that the dates of flowering, 

 given in the general Floras of Hooker and others, cannot be considered as 

 apphcable to the whole of Britain, and this district presents, among others, 

 one striking example. The Hydrocotyle vulgaris is stated in the British Flora 

 to flower in May and June : we have never seen it here in this state earlier 

 than the end of Jul}', and generally not till August or September. However, 

 as this species mostly grows in marshy places, it is therefore much exposed to 

 the influence exercised by the neighbourhood of copious springs. 



