Mededeelingen ’s Rijks Herbarium Leiden: 
No. 18. Notes on the types of Polyporus in 
Persooon’s Herbarium 
BY 
H. A. A. VAN DER LEK. 
The Herbarium of Persoon in the Rijks Herbarium at Leiden is 
of the greatest interest in connection with many mycological ques- 
tions of classification and nomenclature. Many well known mycolo- 
gists have made a careful study of the types, preserved in the 
eollection and have expressed their opinion in different notes added 
to the specimens. A comparison of these notes is of the highest 
interest. 
The object of the present paper is to bring together the notes 
that have been added to the different speeimens of Polyporus, 
Polystictus and Fomes. In many cases l added further notes of my 
own, which [ made during the last two years. Many of these notes 
are based on correspondence 1 have had with M. BRESADOLA, to 
whom 1 sent a great many specimens for comparison. For this 
and for many other kindnesses, [ am glad to offer him my sincere 
thanks. 
POLYSTICTUS. 
Polystictus abietinus. 
It is interesting to observe in PersooN’s collection, the great 
variability of this species („lmmensae confusionis mater,” Irres) a 
fact which was evidently appreciated gradually by him. 
We find this species in his collection uader the names: 
1. Boletus abietinus, in cover sub N°. 910, 262—790; Polyporus 
abietinus, sub N°. 910, 2W2—793, and N°. MO, 262—790. 
2. Sistotrema wviolaceum, in cover sub N°. 910, 270—433 and 
N°. 910, 270—423, both of Moucrot. To the latter PERSOON noted: 
„Sistotrema violaceum.” In his Synopsis (p. 552) Persoon says: „Boleto 
