No. 18. V. d. Lek, Persoon’s types of Polyporus [1913]. Zi 
the greater number of French mycologists this species is called 
„Fomes nigricans” and it is beautifully figured under this name 
by Bouprer. 1) 
Fomes igniarius of the French mycologists is, according to LLovyp, 
„une toute autre plante”, growing on oak, and called Fomes robustus 
by KARSTEN. This fungus is to be found, as Lroyp mentions, in 
France as well as in Sweden; nevertheless neither PERSOON, nor 
Fries have distinguished it as a species. 1 found it also in Holland 
on oak and on Hippophae rhamnoides. 
Fomes nigricans FR. according to BRESApOLA and Lroyp, is only 
a black form of Fomes fomentarius, judging from the specimen at 
Berlin, cited by Fries: „Scotia Krorzen.” [Cest une forme noire 
de fomentarius et ce fut l'idée primitive sans doute de Fomes nigri- 
cans „ad truncos Betulae nec alibi”’| (Lroyp. Myc. Note 35). 
Yet it should be observed that, to judge from the Hym. Eur. 
Frres?) has distinguished the different forms under which fomen- 
tarius can appear: „Optimus, vegetior copiosum fomentum molle 
quotannus edens, ad Fagos abunde; minor, macrior et durior 
ad Betulas. Whereas, speaking of Fomes nigricans, he says: 
„Forma fere praecedentis, sed certe diversus.” 
Fomes laccatus Pers. Myce. Eur. IL. p. 54 (mot 0% as Frres and 
SACCARDO mention) — Fomes lucidus (Leys) Fr. A small specimen 
of this species in box 350. 
Boletus obtusus. 
Under this name Persoons) gives a description of a form of 
Fomes igniarius. So we find in his collection (box 4) a young specimen 
of Fomes igniarius labelled by Persoon: „Boletus Polyporus obtusus 
(juvenilis) B. igniarius 
Fomes pomaceus. 
In box 105 we find some good specimens, labelled by PeRrsooN: 
„Polyporus pomaceus”’, a plant undoubtedly closely allied to Fomes 
igniarius. Thus Persoon t) describes it as a variety of Boletus fomen- 
tarius (B. pomaceus) immediately following on B. obtusus; in the 
Mye. Eur. (IL p. 84) it is given as a separate species. FRIES 5) con- 
siders P. pomaceus as as a variety of Polyporus igniarius. For me 
also it is probably only a form (the Amygdalaceae-form) of Fomes 
igniarius. In Lroyp's opinion the differences are sufficiently great 
1) leones mycologicae PI. 155. 
2) Hym. Eur. Ed. Alt. p. 558 en 559. 
3) Synopsis p. 5388. 
4) Synopsis p. 538 
5) Hym. Eur. Ed. Alt. p. 559. 
