XXX NOTES ON THE FLORA OF CLYDESDALE. 



station of Dr. Taylor, and in Glen Boy, where it is comparatively 

 abundant. D. Daldinianus is a luxuriant moss, and on the hills 

 behind Dunoon and Kilmun has been gathered in huge tufts with 

 stems 3 or 4 inches in length, in this respect at least quite a contrast 

 to the other. Fruiting specimens of this moss have been found on 

 Ben Ledi and near Crianlarich. 



As comparatively little attention has been paid to the Hepaticae, 

 this part of the subject may be dismissed with a few remarks on the 

 distribution of one or two of the more peculiar. 



The magnificent Physiotium cockleariforme is prevalent on all the 

 more prominent of our western mountains, and obtrudes its beautiful 

 purplish tufts especially on the grassy slopes facing the west. Two 

 forms are apparent, one being much more slender and the colour 

 less deeply marked, otherwise there is little difference observable, 

 although hopes have been entertained by more than one continental 

 botanist that a second species is admissible. 



Adelanthus Carringtonii (Balfour) is seen occasionally in similar 

 situations to the above, and nowhere in greater luxuriance than on 

 Ben Voirlich ; also on Ben Lawers much more sparingly. 



Until within the last four or five years the study of Lichens in the 

 western parts of Scotland has not engaged the attention of botanists. 

 This is mainly owing to the field of research not being favourable. 

 As in the case of other large manufacturing towns, the atmosphere 

 of Glasgow and its neighbourhood is not suitable to the growth and 

 development of lichens, indeed within a distance of 10 miles of the 

 city scarcely a lichen in a state of fructification is to be seen. A few 

 of the more common Parmelice, including P. physodes, may be seen 

 covering the stems of the older trees in certain inclosures and 

 secluded glens, along with the cosmopolitan Lecanora subfusca and 

 several of its varieties in fruit, and perhaps Lecidea parasema and 

 Graphis scripta, both in a sickly state; but with these exceptions 

 scarcely any others can be said to be recognizable. 



As is well known lichens are peculiarly susceptible to atmospheric 

 changes, and may, indeed, be reckoned as a test of the purity of the 

 air, and the least traces in it of the mineral acids, more especially, are 

 sufficient to arrest their growth, and even destroy the more delicate. 

 It is not until Kilsyth is reached on the east, and Upper Blantyre on 

 the south, that any of the crustaceous lichens appear in a healthy active 

 state of growth ; and even although these adverse atmospheric con- 

 ditions are in some respects changed, the extremely slow rate of 

 growth of these vegetable organisms forms another barrier to their 

 study. 



It is only on the outskirts of our district, such as Ben Ledi, Cal- 

 lander, Killin and Ben Lawers, "Western Isles, &c., that lichenologists 

 have pursued their researches with continuous vigour, and as even 

 these, with one or two exceptions, have been but partially investi- 

 gated, generalizations on the distribution of this tribe are impossible. 



