512 



LICHENACEI. 



[PHLTCTIS. 



or murali-divided. 

 sterigmata. 



Spermogones with simple or slightly branched 



usually more 



X-350 



ft 



X-250 



Fig. 72. 



open, and especially in the spores being murali-divided. It comprises 7 

 genera, four of which are entirely exotic, while Belonia Koerb., though 

 European, does not occur in Britain. 



64. PHLYCTIS Wallr. Naturg. 

 der Flecht. (1825) p. 527. Thalhis 

 thinly crustaceous, continuous or 

 pulverulent. Apothecia rotundato- 

 difform, usually suffused, erumpent, 

 the thalline margin irregularly 

 dehiscent or indistinct ; hypo- 

 thecium colourless ; spores large, 

 l-2nae, ellipsoid or oblong, murali- 

 divided, colourless ; paraphyses 

 slender ; hymenial gelatine scarcely 

 tinged, but the thecse bluish with 

 iodine. Spermogones with simple 

 sterigmata and short, slender, 

 straight sperm atia. 



A small genus the plants belonging Phlyctis agdcea Koerb. A. A 2- 

 to which are, from the appearance of spored theea and paraphysis, X 

 the fructification, readily overlooked. 250. B. Two spores, X350. 

 In some respects it approaches Pertu- 



saria, but is definitely separated by the muriform spores. Of the three 

 European species two are found in this country. 



1. P. agelaea Koerb. Syst. Lich. Germ. (1855) p. 391. Thallus 

 effuse or subdeterminate, thin, rugose or smoothish, often subleprose, 

 white or greyish-white (K + yellow, then deep-red). Apothecia 

 minute, blackish, white- or caasio-suffused ; spores 2nae (3-4nae), 

 ellipsoid, mucronate at the apices, 0,045-70 mm. long, 0,014-27 

 mm. thick. Mudd, Man. p. 279, t. 5. f. 118 ; Cromb. Lich. Brit, 

 p. 61 ; Leight. Lich. Fl. p. 246, ed. 3, p. 237.The7otrema ayelcea 

 Gray, Nat. Arr. i. p. 494 pro parte. Variolaria agdcea Turn. & 

 Borr. Lich. Brit. p. 78 ; Sm. Eng. PI. v. p. 171. Lichen agelceus 

 Ach. Prodr. (1798) p. 30 ; Eng. Bot. t. 1730. Variolaria con- 

 stellata Tayl. in Mack. Fl. Hib. ii. p. 113 pro parte (ex specimiue 

 ab ipso). Brit. Exs. : Leight. n. 282 ; Mudd, n. 269. 



Occasionally speads very extensively and then covers the lower portion 

 of the trunks of trees. The apothecia, which are scattered or more 

 frequently crowded, are at first entirely enclosed in thalline verruca and 

 at length leproso-coronate or almost covered by the thallus. The spermo- 

 gones are very seldom visible in the British specimens. 



Hob. On trunks of trees in maritime and upland situations. Distr. 

 General and common in England ; scarce in S. Ireland ; not seen from 

 Scotland or the Channel Islands. B. M. : Ickworth, Suffolk ; near 

 Yarmouth, Norfolk ; Epping Forest, Quendon, and Rickling, Essex ; 

 Penshurst, Kent : Shiere, Surrey ; Glynde and Ilenfield, Sussex ; Caris- 



