198 LICHENES. [Parmelia. 



On trees, in mountainous countries ; especially near the sea and near 



lakes. 



3. P. microphyllum, (small-leaved Cushion Placodiuni); thal- 

 lus slightly imbricated depressed fragmentary on a dense black 

 fibrous cushion, its segments grey lobed crenated and granu- 

 lated at the edge, apothecia tawny with a paler smooth border. 

 Sm. — Lichen microphyllus, Schrad. — E. Bot. t. 2128. — Lecidea 

 microphylla, var. triptophylla, Ach. Syn. p. 53. 



On trees, Bodmin, Mr. D. Turner. Loch Katrine and other places 

 in the Highlands of Scotland. 



4. P. dcedaleum, (Jine-lobed imbricated Placodiuni); thallus 

 closely imbricated radiated membranous very smooth brownish- 

 grey pale with black fibres beneath its segments linear obtuse 

 undulated, apothecia black with a black border of their own 

 substance. Sm. — Lichen dcedaleus, E. Bot. t. 2129. 



Scotland, on rocks ? Mr. Menzies. (E. Bot.) 



III. Thallus loose, scarcely attached, except by Jib res or radicles 

 or a small base, to the substance on which it grows. 



A. Upper surface different from the under. 



a. Attachment of the thallus diffuse (not fixed by a central point). 



x. Apothecia scutelliform, discoid, bordered, attached by the centre. 



* Thallus more or less membranaceous. 



Fam. IX. Parmeliace/E. 



18. Parmelia. Ach. Parmelia. 



Thallus foliaceous, membranaceous or coriaceous, spreading, 

 lobed and stellated or laciniated, more or less fibrous beneath. 

 Apothecia (scutellce) orbicular, beneath formed of the thallus, 

 free, fixed only by a central point, the disk concave, coloured, 

 the border formed by the inflexed thallus. — Named from vagMi 

 a small shield, and ifkia, to surround or enclose; in allusion to 

 the apothecia being surrounded by a border of the crust. 



* Thallus with its segments not inflated at the extremity. 



1. P. glomulifera, Ach. (cjlomuliferous Parmelia); thallus sub- 

 cartilaginous orbicular glaucous-grey broadly and irregularly 

 lobed and sinuated, bearing large and tufted warts and excres- 

 cences of a dark greenish-brown colour, beneath tawny and 

 downy, apothecia red-brown with an elevated border. — Ach. 

 Syn. p. 195. — Lichen glomidiferus, Lighif. — E. Bot. t. 293. 



Trunks of old trees, in mountainous countries. 



2. P. caperdta, Ach. {wrinkled sulphur Parmelia); thallus sub- 

 membranaceous orbicular pale sulphur-colour lobed sinuated and 

 crenate granulose in the centre black and hispid beneath, apo- 

 thecia scattered bright chestnut frith an elevated incurved bor- 

 der. Ach. Syn. p. 196. 



