248 THE JOURNAL OF BOTANY 



LICHENS OF ARRAN (v.-c. 100). 



By J. A. Wheldon, F.L.S., and W. G. Travis. 



There appears to be very little in print to indicate to what 

 extent the lichens of Arran have hitherto been investigated. 

 Beyond the mention in Leighton's Lichen Flora of Great Britain 

 and Croinbie's Monograph of British Lichens, of Arran localities 

 for a few lichens, mostly gathered by Prof. J. H. Balfour, of 

 Edinburgh, we know of no published record of earlier work. 



Our paper includes these records, and also the results of field- 

 work done by one of us in July, 1910, and by Mr. Wm. West, F.L.S., 

 in August of the same year. On hearing that we were working at 

 the lichens of the island, Mr. West kindly placed at our disposal 

 a mass of material collected by him. His gatherings, which were 

 particularly rich in corticolous species, have, on examination, 

 yielded many interesting lichens ; and we are much indebted to 

 him for allowing us to supplement our list so materially by the 

 inclusion of particulars of his finds. It may be added that some 

 of the material collected has been distributed through the Lichen 

 Exchange Club, and was referred to in the Report of the Club for 

 the year 1911. 



It should be explained that practically the whole of the field- 

 work was done on the coast, little or nothing being done on the 

 mountains, owing, to some extent, to inclement weather. The 

 eastern side of the island, from Corrie to Lamlash, received most 

 attention ; but some collecting was also done on the western 

 coast between Drumadoon Point and Tormore, and on the south 

 coast in the neighbourhood of Bennan Head and Kildonan. The 

 corticolous species were mainly gathered in the woods about 

 Brodick and Corrie, and in the lower wooded portions of Glen 

 Rosa, Monamore Glen, and other glens opening to the east coast. 

 In Arran lichens are abundant and in fine condition on the 

 shore-rocks ; and most of the saxicolous species in our list were 

 collected on the coast, more especially at Corriegills, just south of 

 Brodick. The outcropping rocks on the shore there are mainly 

 of sandstone and conglomerate, but are intersected by numerous 

 dykes of igneous rocks. 



A note was taken, so far as practicable, of the kind of rock on 

 which the saxicolous species were met with, with a view of ascer- 

 taining to what extent they exhibit a preference for a particular 

 type of rock substratum. The data obtained are hardly sufficient 

 to warrant more than a brief reference to the subject. 



Many of the silicicolous lichens were found to occur indifferently, 

 as might be expected, on siliceous sedimentary rocks (sandstones 

 and conglomerates) as well as on some of the acid igneous rocks. 

 Thus, on sandstone rocks on the shore at Corriegills the following 

 lichens were noted as common: — Physcia aquila, Xanthoria parie- 

 tina, Lecanora parella, L. atra, Verrucaria maura, Callopisma ferru- 

 (jineum var. festivum, Lecanora campestris, Ramalina cuspidata, 

 Physcia stellaris, P. tenella, and Placodium tegularis. These 



