96 Rev. T. Salwey : List of the scarce Lichens found 



Lecanora periclea. This is an obscure and by no means a com- 

 mon lichen. It grows with us occasionally upon old oak- and ash- 

 trees ; upon an ash-tree in a field south of Treflach-lane, about a 

 quarter of a mile from Croeswilin. 



L, squamulosa. On the Moelydd, and upon the rocks at Pentre- 

 gaer. 



L. glaucocarpa. Craig-y-Rhu, but barren. The crust of this 

 plant consists of a number of thick, smooth, hard scales, here and 

 there collected together, but more usually scattered, wavy, and 

 rounded in the centre ; in colour varying from a glaucous to a dark 

 brown in an old state, and the younger ones white at the edges. It 

 grows upon the perpendicular face of a limestone rock. 



L. rubra. This is a very beautiful lichen and of rare occurrence. 

 The only two habitats I know for it are upon the walls of Wigmore 

 Castle in Herefordshire, and at Craig-y-Rhu in the parish of Oswes- 

 try. In both habitats the plant grows upon patches of decayed 

 Hypna hanging loose from the stone. 



L. hcematomma. Craigforda, Craig-y-Rhu, &c. 



Parmelia glomulifera. Upon a wych-elm at Llanforda. There is 

 only a single plant of this upon the tree in question, and it is at pre- 

 sent the only English habitat I know for it. I have watched this 

 plant for upwards of twenty years, and cannot perceive that it has 

 either increased or decreased. It has glomeruli, but no apothecia ; 

 many of the Parmelice certainly seem to propagate themselves by 

 buds or gonidia without apothecia. The shields of scortea and of /a- 

 nuginosa are I believe yet a desideratum in English botany, and those 

 oi proboscidea, perlata, Borreri and others are very rare, even where 

 the plant itself is not uncommon. I cannot but suspect from the 

 above instance, that the apothecium is at all events the only mode 

 by which this particular species is propagated. Dr. Taylor considers 

 the glomeruli of the present plant as the only distinction between 

 this and herbacea. I confess I cannot be of this opinion. Even Fries, 

 so prone as he is to diminish species, though he removes both of 

 these to the genus Sticta, and in which I think they may well be 

 placed, still keeps them distinct. Dr. Taylor also considers that they 

 would rank as well with the Stictce as with the Parmelice. Both of 

 them grow in great profusion in the wooded parts of Wales, often 

 upon the same trees ; but whether in a wet or dry state, they equally 

 strike the eye as being distinct ; but most so in a dry state, the smoky 

 white colour of the thallus of the glomulifera contrasting with the 

 brownish green of that of herbacea. It is also thicker and more 

 leathery, and not so much wrinkled. 



P. herbacea. Upon an old vv^ch-elm on Bringewood Hill, oppo- 

 site Downton Castle, in Herefordshire. 



P. caperata. Craigforda and other places about Oswestry, but not 

 common, and usually barren. 



P. conspersa. Craigforda: not common. The var. stenophylla oi 

 Ach. grows upon the sandstone rocks there. 



P. Borreri. Woodhill and Porkington, but with us always barren ; 

 this plant is scarce with us. 



