1914-15.] BOTANICAL SOCIETY OF EDINBURGH 353 



plants resembling a seaside flora. The vegetation here, 

 however, is not fully typical of a seashore. For, although 

 the low-lying land along the margin of the Bay has every 

 appearance of being swept by the higher tides during the 

 stormy months of the year, the waters of the Bay are 

 estuarine, and the comparatively low salinity renders the 

 flora characteristic of a brackish-water area rather than of 

 the seaside proper. The plants are not those characteristic 

 purely of sea-coast, but those found both on sea-coast and 

 beside brackish water. Such plants as are frequent along 

 the seaboard of Ayrshire or Fifeshire, as Galystegia 

 Soldanella, Br.; Eryngiu/m maritimum, Linn.; Thalic- 

 trurn minus, Linn.: Astragalus danicus, Hehz., were not 

 found by the Culbin Sands. 



The dominant plants of this salt-marsh association are 

 Statice maritirna. Mill.; Plantago Ooronopus, Linn.; 

 Littorella uniflora, Aschers (lacustris, Linn.): Glaux 

 maritirna, Linn. ; Gochlearia officinalis, Linn.: Triglochin 

 maritimum, Linn.; Aster Trypoliwm, Linn.: Juncus 

 squarrosus, Linn.; Carex Gtoodenowii, Gay. 1 



A specially noticeable feature in this area is the domi- 

 nance of the Statice maritirna. It increases in abundance 

 nearer the water, and here also its foliage is particularly 

 red. This plant shows most distinctively among the 

 littoral species the cushion growth which is characteristic 

 of so man}' of the dune plants. 



2. Fixed Dunes. 

 (a) Sandy Flats. (See Map III.) 



Westward of the salt-marsh the surface continues at 

 about the same level ; but the soil is more or less deeply 

 composed of sand. On the dry flats here the mat-like or 

 cushion growths are better exhibited than in any other 

 association of the Culbins. On certain parts of the fairly 

 firm sand Calluna vulgaris. Hull., is dominant, and its 

 habit is this mat-like growth, in dense compact circles 

 sometimes more than a yard in diameter, more often from 

 12 to 18 inches. Between these mats are bare spaces of 



1 In this and other lists of plants throughout the paper, the species 

 are given in rough order of frequency of occurrence. 



