Friesia III, 5

MARASMIUS PERONATUS AND MARASMIUS
PERFORANS FORM HYDROCYANIC ACID
By ERNA BACH
Labora t ory of Plant Physiology of the Royal Veterinary and Agricultura l
College. Copenhagen.
Marasmius peronatus (Bolt.) Fr. (M. urens (Bull.) Fr.) and
M arasmius perjerems (Hoffm.) are both cyanogenic, which means
they form hydrocyanic acid (HCN). Both species, collected on 19th
oct. 1947 in the coniferous wood Tisvilde Hegn in north-eastern
Seeland, gave off hydrocyanic acid as was indicated by paper dipped
in picri acid and Na:lCOS (for method see M ti Il e r, Friesia 3) 52,
1944). Including these ' two new species the cyanogenic mushrooms
now number 23 species in all.
In an outstanding paper L o q u i n (Bull. Soc. Linn. Lyon 13) 151,
1944) c1aims that all basidiomycetes are cyanogenic, but the amount
of hydrocyanic acid is in most cases so small that it can be detected
only by 5 % (SCN) 2CO giving a blue colour with traces of hydrocyanic
acid.
The following other H ymenomycetes (21 species) have previously
been noted as cyanogenic giving sufficient hydrocyanic acid as to be
detected by odour or with picric acid paper:
Polyporaceae
Polypor u s j rondo su s (Heinemann, Bull. Soc. Myc. F r a . 58) 99, 1942 ) ;
Tramete s amygdalea (Ma ire, Bull. Soc. Myc. F ra . 38) VII, 1922 & 42) 40,
19 26 ) .
Agaricaceae
Gantharellus carbonarius (Heinema nn, Bull. So c. Myc. F r a . 55) 121, 1939) ;
Glitocy be alexandri (Heim , Bull. Soc. Myc. F ra . 44) XXVI, 1928);
Gl. clavipes (Bousse t, Soc. Linn. Lyon. Bull. mens. 10) 154, 1941);
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