BOTANY 



neighbourhood of Brickhill and Burnham, an extremely large number 

 of species are to be found. They are necessarily very uncertain in 

 appearance, depending as they do so much upon climatal influences, so 

 that a long period is required before a district, even of limited dimen- 

 sions, can be said to be exhaustively explored. Their occurrence 

 depends to so great an extent upon the higher forms of life, for instance 

 upon the proper quantity of dead wood, decaying vegetable matter or 

 the like, and in few, if any, instances is food obtained directly from the 

 soil. 



Space will not allow of anything like a complete list, even of the 

 species known to grow in the county, being given here, but in passing 

 we may mention that the genera Amanita, Russu/a, Agaricus and Boletus 

 are well represented. The poisonous A. muscarius is often very common 

 in Black Park, at Wilton Park and Dropmore, and the even more poi- 

 sonous A. pballoides occurs near Princes Risborough, where Tricboloma 

 spermatica is also found ; Lepiota vittadini has been found near Bledlow ; 

 Clitocybe dealbatus and C. laccatus at Burnham ; Collybia esculenta at Lane 

 End ; Clitopilus prunulus near Halton ; Hebeloma crystallina, H. geophila and 

 H. concentrica at Brickhill ; Coprinus micaceus and C. atramentarius on the 

 rubbish heaps near Iver ; Lactarius piper atus, L. deliciosus, L.fuliginosus near 

 Halton ; Russu/a nigricans, Brickhill ; R. emetica, R. ocbroleuca, R. a/utacea, 

 and R. rubra about Black Park ; Cantharellus cibarius near Farnham ; Bole- 

 tus luteus, B. luridus, B. edulis, B. flaws, at Brickhill, etc. ; Fistulina bepatica, 

 Wilton Park ; Hydnum auriscalpium, Marlow woods ; Hirneola Auricula- 

 yudce, near Wycombe ; Phallus impudicus, very common in the Chiltern 

 woods, and in 1902 especially frequent in a wood near Amersham, also 

 in the Brickhill pine woods ; the puff ball Lycoperdon giganteum, and the 

 smaller members of the genus, as L.gemmatum, saccatum and pyr 'if or 'me, have 

 been noticed about Brickhill. The pretty Cyatbus verm'cosus was found 

 near Buckingham. The ' rusts, smuts, mildews and moulds,' which in 

 some instances are such deadly foes to the agriculturists, market garden- 

 ers, or horticulturists, are too well represented. As an instance of leaf- 

 fungi one may draw attention to a common example in the sycamore, 

 where the unsightly black patches on the leaves in the autumn are caused 

 by the fungus Rbytisma acerinum ; another is the well known wheat rust 

 (Puccinia graminis), one of the pests which it is said is referred to in the 

 Old Testament. For many ages it was supposed to be connected with the 

 occurrence of the barberry (Berberis vu/garis), and edicts were promulgated 

 to destroy the plant in certain countries, but the botanists of the early part 

 of the nineteenth century proved to their own satisfaction that the 

 barberry could not have this malevolent influence, since the fungus which 

 grew upon it was a different species from that which was found upon the 

 wheat, the former being Mcidium Berberidis, the latter Puccinia graminis, in 

 fact belonging to two different genera. It was however reserved for De 

 Bary to prove that these two widely differing fungi were really only two 

 different stages in the life history of a single individual species, and 

 demonstrated it by sowing the aecidiospores of the barberry upon the 

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