514 



LICHENACEI. 



[THELOTREMA. 



p. 45. Lichen lepadinus Ach. Prodr. (1798) p. 30. Lichen in- 

 clusus Eng. Bot. t. 678. Brit. Exs. : Leight. n. 121 ; Mudd, 

 n. 268. 



X-30 



X-25O 



Fig. 73. 



Thelotrema lepactinum Ach. A. Section of apothecium, X 30. B. Theca and 

 paraphyses, X250. C. Two spores, x350. 



The thallus varies somewhat in thickness, and at times, especially 

 when growing on holly, is determinate and marked by a narrow, black, 

 hypothalline line. In a young state the apothecia might be taken for 

 those of a Pertusaria, but when fully developed they are very different 

 in appearance. They are usually more or less scattered, but occasionally 

 in old plants become crowded. 



Hab. On smooth bark of trees from maritime to upland tracts. Distr. 

 General and common in England ; rarer in Scotland ; apparently very 

 rare in Ireland. B. M. : Ugley and Walthamstow, Essex ; Ightham, 

 Kent ; St. Leonard's Forest, Sussex ; New Forest, Hants ; Ilsham Walk, 

 Torquay, S. Devon; St. Breock, Cornwall; Bagley Wood, Berks; 

 Bardon Hill, Leicestershire ; Holly bush Hill, Malvern, Worcestershire ; 

 Cwm Bychan and Barmouth, Merionethshire ; Hafod, Cardiganshire ; 

 Haughmond Hill, Church Stretton, and Acton Burnel Hill, Shropshire ; 

 Baysdale, Cleveland, Yorkshire ; Teesdale, Durham ; Calder Abbey, 

 Cumberland ; Felton Woods, Northumberland. Foot of Ben Lomond, 

 Dumbartonshire ; Barcaldine and Appin, Argyleshire ; Glen Falloch and 

 Loch Katrine, Perthshire ; Morrone, Braemar, Aberdeeushire. River- 

 stone, co. Cork ; Killarney, co. Kerry. 



Var. /3. scutelliforme Ach. Lich. Univ. (1810) p. 312; Syn. 

 p. 115. Thallus effuse, thickish, unequal, at times subpulverulent, 

 cream-coloured. Apothecia prominent, somewhat large, crowded, 



