A 



NEW LICHEN, GONGYLIA VIRIDIS A.L.Sm. 

 IN SURREY AND ESSEX. 



r5v ROBERT PAULSON, 



.R.M.S. 



A Ni-:w liclK-n ^Towinj,' on the sandy bank of a foot- 

 path in the neighbourhood of Horsle\', Surrey, and 

 named by Miss A. Lorrain Smith. Gonfiylia viridis. 

 was first collected by Mr. B. W. [. Starling, in 

 Februar\', 1910. Since 

 that date it has been 

 recorded hv Mr. Percv 

 Thompson from three 

 separate localities of 

 Epping Forest, all in 

 the vicinitN' of Loughton 



It 

 re- 



^athered 

 spot in 



and Theydon Bois 

 has again, quite 

 centl\'. been 

 from another 

 Surrey, by Mr. .Starling. 

 The finding of this 

 lichen in Epping Forest 

 was not a result of the 

 discovery in Surre\-, as 

 it was sent for identi- 

 fication with other 

 material that hail been 

 collected, both at the 

 Esse.x Field Club Lichen 

 and Moss Fora\' held in 

 November last and at 

 periods previous to that 

 date. It was, most 

 probably, first collected 

 in the Forest in April. 

 1910. 



There is little matter 

 for surprise that this 

 plant has hitherto been 

 overlooked, for its thin, 

 green, crustaceous 

 thallus grows upon the 

 ground and takes, as it 

 spreads over the surface, 

 all the irregularities of 

 the soil. To an\one 

 standing erect it appears 

 as a green discoloration 

 of the ground similar to 

 that given by algae in 

 damp places. It might 

 easily be passed over, 

 when not fertile, as the 

 immature thallus of 

 Boeomyces roseiis. The 





sand\- bank at 



Horsle\' 



has a southern aspect, so that the plant is fullv 

 exposed to the sun, there being little or no shade 

 there. In Epping Forest this lichen occurs on 

 sandy soil around gravel pits, and in one case it is 

 on the perpendicular face of the digging, but all the 

 Forest localities are more or less shady, thus shovvini' 



that an exposed sunn\' situation is not essential, as 

 might have been inferred if the Surre\- plant alone 

 had been found. 



The genus Goimyliu belongs to the \'errucariaceae 



and has representatives 

 in North and Central 

 Europe: it is now, for 

 the first time, included 

 in the flora of Great 

 ISritain. The accom- 

 jiaining photograph b\- 

 Mr. A. W. Dennis shows 

 the chief characters of 

 this plant, viz. : the 

 thin thallus, exhibiting 

 all the roughness of 

 the ground, and the 

 numerous g 1 o bo s e , 

 shining, black fruits, 

 pcrithccia. with a de- 

 pression at the toj) of 

 each. Microscopic ex- 

 amination is necessary 

 to make out other 

 miportant characters of 

 this species. The size 

 and shape of the spores 

 must be known for the 

 [)urposes of exact deter- 

 mination. The fertile 

 period is apparent!}- at 

 Its best during the earh- 

 months of the \ear. 



Interesting questions 

 arise respecting the 

 present distribution of 

 this plant, such as : How 

 wide a range has it in 

 the southern counties ? 

 Does it extend farther 

 north than Essex 'f It 

 should be looked for on 

 sandy banks and mounds, 

 both in sunn\' and more 

 or less shad\- spots. 

 Ejiping Forest would 

 a[)pear to most lichenists 

 as a very unlikeh- locality 

 for a new plant. 



The diagnosis of 

 Goni^y/ia viridis appeared for the first time in the 

 Joiinuil of Botany, \'olume 49, Februar\-, 1911, 

 and it was discovered just in time to be included in 

 the second volume of the Monograph of British 

 Lichens which has been prepared by Miss A. 

 Lorrain Smith, F.L.S., and printed, 1911, b\- order 

 of the Trustees of the British Museum. 



h' A. 



1. Goii^ylia lurulis A.L.Sm. 



M.'iynitieLi lwi_-iil\ -l!\e tiilits. 



//'. Pciiuis. 



184 



