Milk-white Toothed Polypore

Album description

Irpex lacteus (Fr.; Fr.) Fr. Elench. Fung. p145, 1828, syn.: Sistotrema lacteum Fr.
Milk-white toothed polypore, DE: Milchweisser Eggenpilz
Slo.: belkasti rašpovec

Dat.: Feb. 23. 2014
Lat.: 46.35947 Long.: 13.70424
Code: Bot_784/2014_DSC0038
File names: from Irpex-lacteus_raw_1.xxx to Irpex-lacteus_raw_8.xxx.

and

Dat.: Feb. 27. 2014
Lat.: 46.35947 Long.: 13.70424
Code: Bot_786/2014_DSC0132
File names: from Irpex-lacteus_raw_10.xxx to Irpex-lacteus_raw_11.xxx.

Habitat: alpine valley, an opening in mixed forest with predominantly Fagus sylvatica followed by Picea abies; modestly inclined southeast oriented mountain slope, overgrown calcareous ground composed of scree, rocks and boulders; mostly in shade, partly protected from direct rain by tree canopies; average precipitations ~ 3.000 mm/year, average temperature 7-9 deg C, elevation 560 m (1.950 feet), alpine phytogeographical region.

Substratum: cut down trunk of Fagus sylvatica lying on ground, in its late initial phase of integration; the trunk was massively infected also with Trametes hirsutum.

Place: Lower Trenta valley, between villages Soča and Trenta, right bank of river Soča, near 'Na melu' place, East Julian Alps, Posočje, Slovenia EC.

Comments: fruit body mostly resupinated but also effused-reflexed; very large, about 1.5 m x 20 cm, about 2-3 mm thick, context thinner than pore layer; small 'pilei' up to 8(12) mm off the substrate; hymenophore with initially distinctly irregular angular, almost labyrinthine pores soon becomes irpiciform to hydnoid (compare Figs. 8. and 10.); smell indistinctive, taste initially indistinctive, after some time slightly unpleasant; 5% KOH reaction on context and pore layer mild, color changed to somewhat darker ocher-beige; SP abundant, white-yellowish with a slight green tint, oac014. No hypha clamps have been observed. All observed traits fit well to expectations for Irpex lacteus except cystidia. The fact that I haven't found conspicuously encrusted cystidia puzzles me.

Spores smooth. Dimensions: 5.1 [5.9 ; 6.2] 7.1 x 2.5 [2.8 ; 2.9] 3.2 microns, Q = 1.9 [2.1 ; 2.2] 2.4; N = 47; C = 95%; Me = 6.1 x 2.8 microns; Qe = 2.2. Basidia dimensions approximately 20 x 4.5 microns.Olympus CH20, NEA 100x/1.25, magnification 1.000 x, oil, in water (spores) and NEA 40x/0.65, magnification 400x, in water, congo red (hymenium, cystidia). AmScope MA500 digital camera.

Herbarium: Mycotheca and lichen herbarium (LJU-Li) of Slovenian Forestry Institute, Večna pot 2, Ljubljana, Index Herbariorum LJF

Ref.:
(1) Personal communication with Mr. Bojam Rot, www.gobenabovskem.com
(2) A. Bernicchia, Polyporaceaes.l., Fungi Europaei, Vol. 10., Edizioni Candusso (2005), p 296.
(3) L. Ryvarden, R.L. Gilbertson, European Polypores, Fungiflora, Vol.1. (1993), p 352.
(4) G. J. Krieglsteiner (Hrsg.), Die Grosspilze Baden-Württembergs, Band 1, Ulmer (2000), p 329. (5) J. Breitenbach, F. Kraenzlin, Eds., Fungi of Switzerland, Vol.2. Verlag Mykologia (1984), p 176.
(6) http://www.messiah.edu/Oakes//fungi_on_wood/poroid%20fungi/species%20pages/Irpex%20lacteus.htm