A HISTORY OF NORFOLK Lecano-Lecideci, Nyl. {continued) — Graphidei, Nyl. {continued) — Lecidea alboatra, Nyl. Seething Opegrapha lyncea, Borr. Holt var. epipolia, Ach. Market Dere- Arthonia epipasta, Leight. Thorpe ham and near Yarmouth — cinnabarina, var. kermesina, Schser. — expansa, Nyl. Thetford Near Earsham and Holt — Turneri, Leight. Trigby Church Stigmatidium crassum, Dub. Holt — myriocarpa, DC. Thetford Warren Pyrenocarpei, Nyl. and near Kingi Lynn Endocarpon hepaticum, Ach. Near }^or- Graphidei, Nyl. wich Graphis scripta, Ach. Coltishall Verrucaria Garovaglii, Mut. Thetford Opegrapha notha, Ach. Yarmouth — muralis, Ach. Near Yarmouth — pulicaris, Nyl. Lakenham — viridula, Ach. Yarmouth — varia, f. tigrina, Leight. Hadiscoe — epigaea, Ach. Near Norwich — atra, Pers. Holt — nigrescens, Pers. Thetford — Leightonii, Cromb. Near Yarmouth FUNGI When one remembers that Norfolk is the fifth county in England in point of size, one naturally expects its fungus flora to be pretty ex- tensive. And such is the case, with our heaths and bogs, our woods and pastures, our chalk downs and sandy wastes, our sea coast and our broad- land, Norfolk has a pretty varied mycological flora. The fact that saprophytic fungi are very much confined to their own special food-stuffs is gradually coming to be more and more recognized — woodland and pasture-land, heath and roadside have their own particular denizens. Further than this even, the wood of deciduous trees and that of fir trees has each its own special fungus flora. This is a point Fries constantly reiterates in the Monographia. But we may go further still and say that many of the larger Hymenomycetes occur only on the detritus of certain plants and trees or that they are associated with them while they are alive ; for instance, Amanita muscaria occurs only under birch trees ; Collybia radicata, Russula fellea and emetica are found under beech ; Lactarius deliciosus near Scotch firs ; Naucoria escharoides in the humus of alders ; Collybia vertirugis on the dead stems of the previous year's braken plants. Whether these species are saprophytes pure and simple or whether any symbiotic connection exists between these fungi and the tree-roots is a point which merits working out. We all know that certain species are found only on certain dead tree-trunks or branches such as Pholiota heteroclita on poplar ; Armillaria mucida on beech ; Leptonia euchroa on alder ; Polyporus ulmarius on elm ; P. fraxineus on ash ; P. dryadeus on oak, etc. ; but here the element of parasitism comes in, although the boundary line between parasitism and saprophitism is not nearly so pronounced as it formerly was. There are many biological problems connected with the Hymeno- mycetes which still require working out, but hiatus after hiatus has been filled up in this respect during the last decade, so that many species which used to be passed by as common and uninteresting are now objects of considerable interest ; for example, Armillaria mellea and Polyporus annosus (Trametes radiceperda, Hartig) on living timber, of which our county affords only too many examples. 72
