Macrolepiota olivascens , a new species for Poland

The article presents a new for Poland species of fungi, Macrolepiota olivascens M. M. Moser & Singer, found in Milechowy reserve near Checiny in the western part of the Gory Świetokrzyskie Mountains. Morphological characters of the specimens are described and illustrated in the paper.


INTRODUCTION
The genus Macrolepiota Singer (Agaricaceae, Agaricales, Basidiomycota) is represented in Europe by 17 species (Horak 2005); in Poland, until now, 6 species of this genus was found (Wojewoda 2003).Differences between particular species concern among others the fruit-bodies morphology, including the size of fruit-body, the occurrence and colour of scales on the cap and the stipe, the structure of the ring, as well as the microscopic features.Differences concern also the occupied habitats.As a result of molecular studies (Vellinga et al. 2003) the genus Macrolepiota turned out to be heterogenic and was divided into two genera Macrolepiota and Chlorophyllum Massee.Among the species listed from Poland to the genus Chlorophyllum only Macrolepiota rachodes was included, whereas M. procera, M. mastoidea, M. konradii and M. excoriata was included in the genus Macrolepiota.The above authors moved Macrolepiota nympharum to the genus Leucoagaricus.
Recently, Macrolepiota olivascens was found in the Milechowy reserve near Chęciny in the western part of the Góry Świętokrzyskie Mountains representing the first finding of this species in Poland.

MATERIAL AND METHODS
The fruit-bodies were observed and collected in the field, dried in the laboratory conditions and examined by light microscopy.Measurements of cheilocystidia, basidia and hyphae were done by the eyepiece micrometer.
The collected specimens are deposited in the Fungarium of the Department of Botany, Institute of Biology, Jan Kochanowski University, Kielce (KTC 4191,4192,4293).
In order to illustrate the floristic composition, and existing phytosociological conditions of the habitat, in which Macrolepiota olivascens was found, one Braun-Blanquet survey was performed.Vascular plants nomenclature is according to Mirek et al. (2002), and mosses according to Ochyra et al. (2003).
Figs 1-3 The cap of the mature fruit-body when fresh can reach 125-215 mm of diameter.The young cap is closed and has oval shape; later becomes convex; the mature cap is plano-spread with a small, rounded umbo.The surface is covered with clearly visible on bright background, brownish tile like arranged scales.The surface in the middle is smooth.The edge of cap is slightly tomentous.The hymenophore is composed of the lamellae, and lamellulas.The lamellae are crowded, bulging out and free.They are white, white-brownish, with a tendency to become pale rosy in colour.The cap, and lamellae when bruised or damaged after a while changed the colour to bright green, olivaceous or grey-olivaceous (characteristic feature for this species, Fig. 1).
The stipe is slim, cylindrical, empty inside, tuberous at the base, 175-420 mm high and 10 mm wide.The base can reach the diameter up to 40 mm.The stipe is the same colour as the cap -on the white background there are very small brownish scales, on the surface of stipe characteristic brownish zigzag pattern often occurs.The remnants of complete velum make on the stem a double ring, which is relatively stable, and it exists for a long period of time.This ring is not attached to the stipe, and it can be moved along the stipe.The flesh when fresh is always white, only at the edges of the canals made by Diptera larvae, may be discoloured to bright red or brunneous-red.In the cap the flesh is carneous, whereas in the stipe fibrillous, lignified.The taste and smell are not too strong, similar to those of Macrolepiota procera.The taste is mild and pleasant, the smell is delicate.
Deposit of the spores when fresh is pale-rosy in colour, whereas when dry (dehydrated) acquires champagne colour.
The cells of pileipellis, and stipitipellis are elongated, cylindrical and thin-walled.These cells under the microscope are colourless, and are parallel to each other (they are palisade like).The measurements, and appearance of these cells are similar to those of Macrolepiota procera (Fig. 3).The pileipellis hyphae are made of several cells.The single cells of hyphae measured 38-93 × 7.5-11.5 μm.
Macrolepiota olivascens displays high similarity to Macrolepiota procera.These similarities concern, among others, the structure, and appearance of the fruit-bodies.Both species produce large fruit-bodies, and the surface of their caps is covered with distinct tile like arranged scales (Tab.1).They occupy similar habitats -coniferous forests, and brushwoods.
specimeNs examiNed: [ATPOL Ee-72] Poland, Góry Świętokrzyskie Mountains, Chęciny District: Milechowy reserve, near Chęciny, 21.07.2007, leg. J. Jaworska, KTC 4191, 4192, 4293.distributioN aNd habitat.Macrolepiota olivascens is a rare species.It is known in Europe only from several countries.This species was noted in southern Germany (Krieglsteiner 1991), Austrian Alps (Moser 1983), Czech Republic, Hungary (Candusso, Lazoni 1990), Italy (Narducci, Petrucci 1995), Slovenia (Poler 2006), Sweden (Knudsen, Vesterholt 2008), and Turkey (Kaya 2006).In all these countries this species is rare (Horak 2005).In Austria only three stands of Macrolepiota olivascens are known, in Slovenia -known five stands (Boletus Informaticus 2009).In Turkey its fruit-bodies were found in Anatolia, about 1200 m above sea level, in Pinus forest.Whereas according to Horak (2005) it is the subalpine species.This fungus produces the fruit-bodies growing solitary or in groups on the soil mostly in coniferous forests, as well as in other habitats, but in the vicinity of coniferous trees such as pine and larch.The fruit-bodies occur in the summer and autumn.
In July 2007 for the first time the occurrence of this species was confirmed in Milechowy reserve near Chęciny in the western part of the Świętokrzyskie Mountains   After the first finding of Macrolepiota olivascens in July 2007 the species was not found again in that year, and not in 2008, despite the regular observations.

Table 1
Comparison of selected features of Macrolepiota olivascens and M. procera