July 1891.] BOTANICAL SOCIETY OF EDINBURGH. 155 



The Phanerogamic Flora of St Kilda. By 

 Alexander H. Gibson. 



Among the Hebridean Isles there is probably none that 

 surpasses in interest the small Isle of St Kilda. Situated 

 forty miles west of North Uist, within the 100 fathom line, 

 it is, like parts of the Isle of Skye, formed of gabbro and 

 granite. It is hilly, and bounded for the most part by high 

 precipices. Its hills vary in elevation from 700 to 1220 ft. 

 Its soil is turfy on the hill sides, boggy or marshy in the 

 hollows. Abundantly supplied with rain, it has numerous 

 springs, and two small perennial streams, one of which is 

 proudly called by the natives the " avon mohr." Its area is 

 roughly estimated at 3000 acres. 



In the neighbourhood of the south-east bay some ground, 

 the best situated in the island, is cultivated and produces 

 barley of fair quality. In this part of the island vegetation 

 is more luxuriant than elsewhere, and the greatest variety 

 of plants occur. All or nearly all the " introduced " plants 

 are confined to this part of the island. A few plants, e.g. 

 Anagallis tenella, Lychnis Flos-cuculi, find here more genial 

 conditions than are general in St Kilda. Where the vegeta- 

 tion is fully exposed to the strong west winds it is close and 

 compact, of a dark green colour, and composed of Armeria 

 and Plantago. About the nesting grounds of the puffins it 

 is rank, and consists almost entirely of Holcus lanatus, Rumex 

 acetosa, Cochlearia, Atriplex, and Stellaria media. Much of 

 the highest hill, Conacher, is covered with heather. 



The greater number of the species of plants found in St 

 Kilda are represented by numerous individuals in many parts 

 of the island, e.g., Calluna, Sedum Rhodiola, Salix rej)ens, 

 Plantago maritima. A small number of species, however, 

 is limited in numbers and restricted to one or two places, e.g. 

 a patch of Loniccra 500 or 600 ft. up the side of Conacher ; 

 a small colony of Botrgcliium Lunaria ; two colonies of 

 Drosera, etc. 



The species recorded in the subjoined list are very widely 

 distributed in Britain. Only 24 are recorded from fewer 

 than 90 of Watson's 112 divisions. Many of these are 



