34 ANNALS OF SCOTTISH NATURAL HISTORY 



ON THE FLORA OF EIGG. 



By SYMERS M. MACVICAR. 



THE island of Eigg being mostly composed of Tertiary 

 basalts, it would naturally be expected, as is in fact the 

 case, that its flora would closely correspond with that of 

 Mull, which is almost wholly composed of the same forma- 

 tion, and with Skye, of which the greater part is of similar 

 structure ; but it is to be noted that the flora of Eigg also 

 agrees more closely with those parts of Skye composed of 

 other formations than it does with that of the Dalradian 

 schists of the mainland opposite itself. The low altitudes 

 at which the few alpine plants occur in the island as com- 

 pared with those on the nearest mainland are interesting. 

 The scarcity or usually scattered occurrence and the weakly 

 aspect of these plants denote that they are tending towards 

 extinction, and that they are now climatically out of their 

 true home on the warm west coast ; and it seems as if, in 

 their effort to save themselves, they have seized on, or re- 

 tained, the only unoccupied surfaces within reach, viz. the 

 bare face of cliffs, where their long penetrating rootlets could 

 extract moisture from the debris in fissures. Their lower limit 

 is 450 to 500 ft. on the islands, and 1800 to 1900 ft. on the 

 mainland. Salix herbacea, L., is an exception, as it occurs 

 only on the Scuir, descending to about 900 ft., while on the 

 opposite mainland its usual lower limit is 1900 ft, though 

 in one place it descends to 1600 ft. The low altitude at 

 which alpine plants occur is common to our western islands. 

 The following list is the result of visits made to Eigg in 

 1893 an d 1895, when I noted 350 species and varieties. 

 Mr. F. W. Miller also visited the island in 1895, and made 

 a list of the plants seen by him. Unfortunately he did not 

 know at the time of my previous searches, so could not 

 specially look for additions. He very kindly placed at my 

 disposal his list with notes, to which I have appended his 

 initials. In his list there are 23 species and varieties unre- 

 corded by me, making a total of 373 species and varieties 

 a considerable number of plants for an island of 7900 acres, 



