New localities of Protostropharia alcis ( Basidiomycota , Agaricales ) in Poland

The present paper provides new records of Protostropharia alcis in Poland. So far this species was known in the country only from several latest localities in the Biebrza National Park (Biebrza Basin) and the Kampinos National Park (Warsaw Basin). The new localities are situated in the Wigierski National Park (the East Sudetian Lake District) and in the northwestern slope of Mt Wierzejska (the Holy Cross Mountains), where P. alcis was collected on dung of herbivores (eurasian elk and red dear) within several types of forest communities. All specimens of P. alcis were collected in recent years, from late September to early October, in the period 2012-2013. A full description and illustration of P. alcis based on gathered collections are given. Its delimitation, the knowledge of its ecology, general distribution, and threat is also briefly discussed. Based on the new and known distribution data for P. alcis in Poland, its red list category is proposed.


INTRODUCTION
Protostropharia alcis (Kytöv.)Redhead, Thorn & Malloch is a species of coprophilous fungus in the family Strophariaceae produces basidiocarps on faeces of herbivores, primarily on the elk dung.It was originally described by Finnish mycologist Ilkka Kytövuori in 1999, as one of six species in the "Stropharia semiglobata group" in northwestern Europe (Kytövuori 1999), under the name Stropharia alcis Kytöv.As recently as this year, this species was transferred by Redhead (2013a) to Protostropharia Redhead, Moncalvo, Vilgalys -a genus circumscribed to contain Stropharia species characterized by the formation of astrocystidia rather than acanthocytes on their mycelium (Redhead 2013b).The type locality of P. alcis is the rich spruce-hardwood forest situated in the eastern part of Northern Ostrobothnia region in Central Finland (Jussinlamminvaara), where it was found on dung heaps of elk (Alces alces) (Kytövuori 1999).

© The Author(s) 2014 Published by Polish Botanical Society
Describing P. alcis Kytövuori (1999) supported very close relationship of the species with elk dung, reported presence of P. alcis in Estonia, and emphasised its widespread occurrence in Fennoscandia (Norway, Sweden, Finland), where the elk is common and abundant.He also suggested that the distribution of P. alcis must continue towards the east (Russia) and to North America (Canada) owing to the presence of elk, simultaneously being rare or absent in south Europe.Contemporary mycological literature seems to confirm Kytövuori's suggestions in general (cf. Ryman 2008;Viess 2010;Noordeloos 2011;Burzynski et al. 2012), but known collection of P. alcis from hare pellets (Kytövuori 1999), and subsequent records of the species in Italy and Brasil (Rio Grande do Sul), from unidentified dung, probably deer (Noordeloos 2011), and cow dung, or dung-enriched soil (cf.Stropharia alcis var.austrobrasiliensis Cortez & R.M. Silveira; Da Silva et al. 2006;Cortez, da Silveira 2008), may constitute a proof of its wider substrate utilization capability and more extensive global distribution.
In Poland P. alcis has been reported for the first time only in 2012 from the Biebrza National Park (Biebrza Basin) (Kujawa et al. 2012).In the area the species was recorded on elk dung from merely two localities within two types of forest associations which offer different ecological conditions (Vaccinio uliginosi-Pinetum, Tilio cordatae-Carpinetum betuli).There is also the information about unpublished record of the species from the Kampinos National Park (Warsaw Basin) in the mentioned paper.However, both of these findings were issued with any critical notes and illustrations of key micro-morphological characters.During the course of our mycological research in the Wigierski National Park (the East Sudetian Lake District) and in the north-western slope of Mt Wierzejska (the Holy Cross Mountains), new locations of this rare species were noted (Fig. 1).Thus, the main aim of this work is to describe morphologically the collected specimens of P. alcis, and to compare the characteristics with published data.Furthermore, this paper aims to evaluate

MATERIAL AND METHODS
The description of macroscopic features was based on fresh material.Microcharacters of basidiomata were observed with a Nikon Eclipse E-400 light microscope equipped with a Nikon digital camera (DS-Fi1).All microscopic structures were observed in dried material.Free-hand sections of the rehydrated pieces of basidiomata were examined in 5% NH 3 H 2 O. Image-grabbing and biometric analyses were done with NIS-Elements D 3.1 imaging software.Dimensions of microcharacters are given as (minimum) average ± standard deviation (maximum), and additionally in the form of the main data range (10 -90 percentile values).The expression (n = 100, 3, 3) means that 100 microelements from 3 basidiomata originating from 3 collections were measured.Q value refers to the length/width ratio of basidiospores.For basidiospores size measurements, randomly selected mature spores were used, and measured without hilar appendix.The lengths of basidia were measured excluding sterigmata.Leptocystidia dimensions are given as length range × width range × width range (measured at the base and at the apex of cell).Chrysocystidia dimensions are given as length range × width range × width range (measured at the base and at the central -the widest point of cell).The measurements of cystidia refer to their length, base and central width.Statistical computations employed Statistica software (StatSoft).For morphological terminology see Vellinga (1988) and Vellinga, Noordeloos (1999).The nomenclature of forest communities follows Matuszkiewicz (2001).Details of the microcharacters were figured by freehand drawing, with exact proportions and general shapes traced from photographs.The collections studied have been deposited in Museum of Natural History, Wrocław University, Wrocław, Poland (herbarium WRSL), and in the private fungaria of Barbara Kudławiec (BKF, Gniezno) and Błażej Gierczyk (BGF, Poznań).
Basidiomata generally scattered.Pileus 5 -35 mm, hemispherical with a very low, broad umbo, slightly expanding with age, with deflexed then straight margin, not distinctly hygrophanous, not translucently striate, yellowish cream to straw yellow, usually distinctly paler towards margin and more ochraceous at the disk, strongly viscid to glutinous when moist, shining, sticky when dry, glabrous.Lamellae, L = 15-26, I = 3-5, distant, triangular or segmentiform at first, later subventricose, broadly adnate, usually © The Author(s) 2014 Published by Polish Botanical Society somewhat emarginate or with small decurrent tooth, pale grey olivaceous at first then dark grey olivaceous, often clearly mottled (reminiscent a species of Panaeolus), with fimbriate, white edge.Stipe 30-160 × 1.5-5 mm, cylindrical or slightly evenly thickening towards the base, regularly broadened at base, hollow with a narrow cavity, with a thin, faint, glutinous annulus, 5-30 mm below the lamellae, often visible as a line darkened by ripe spores (annular zone), pale yellow in upper half, in basal part deep yellow to ochraceous, above annuliform zone dry, slightly pruinose to minutely pruinose-furfuraceous, below annuliform zone glutinous to viscid when moist or sticky when dry, sometimes faintly girdled with darker lines (Fig. 2).Context concolorous in pileus, darker in stipe (deep yellow to ochraceous).Smell not distinctive.Taste not verified.Spore print color purplish black.

DISCUSSION
For the sake of outward appearance and general habit of basidiomata, there is no doubt that Protostropharia alcis is a conspicuous member of the semiglobata-group.According to Noordeloos (2011), in this group the species can be macroscopically distinguished by rather stout basidiomata, and by the somewhat more intensely coloured pileus and stipe.Moreover, Kytövuori (1999) takes note of dried basidiomata of P. alcis, that in his opinion they are regularly marked by the characteristic white lumps covering the edge of lamellae (e.g. compared with Protostropharia semiglobata (Batsch: Fr.) Redhead, Moncalvo, Vilgalys, where the gill edge looks uniformly minutely white echinate or hairy).The Polish specimens of P. alcis seen by us are somewhat diverse as regards their size, external habit, and colour saturation of pileus and stipe.Some basidiomata are fairly large and sturdy, while others are exceptionally small and frail when compared.Moreover, they vary between themselves in the paler -yellowish cream to darker -straw yellowish colors, and various stipe length to pileus width ratios.Nevertheless, we consider that these morphological differences are not taxonomically significant and can be explained by one or more of the following factors concerning the accompanying weather conditions, the amount of nutrients in the material on which the fungus is growing, and the development stage.It seems that P. alcis can be more easily recognized in the field by its substrate preferences.Most of the occurrences of the species in this study were found on more or less decayed dung heaps of elk (Alces alces).Only few specimens of the material studied has been collected from dung of another herbivore -most probably strongly decayed droppings of red deer (Cervus elaphus), including whole material from Mt Wierzejska and some of those from the Wigierski National Park.These observations confirm a noticeable preference of the species for elk dung.It is worthy to notice that within the studied area of the Wigierski © The Author(s) 2014 Published by Polish Botanical Society National Park, P. alcis seems to be widely distributed in various forest communities (see above).It appears, from September to October, mostly occurring in wetland forests with conifers (Picea abies, Pinus sylvestris) together with Alnus glutinosa, Betula pendula, and B. pubescens -dominated woodlands on swamp peat and wet acid-mineral soils.Its habitat tendency appears to be obviously determined by the areas in which the elk is present and engaged in the specific activity (e.g.feeding, resting) in general.However, at the same time it is not clear if the species is the only member of the semiglobata-group on the area, since so far none of the other has been recorded there.Nonetheless, it can be assumed that like in the northern part of Fennoscandia, P. alcis is nowadays distinctly commoner in woodlands of the Park and perhaps even the whole of north-eastern Poland than P. semiglobata (syn.Stropharia semiglobata (Batsch: Fr.) Quél., S. stercoraria (Schum.: Fr.) Quél., Psilocybe semiglobata (Batsch: Fr.) Noordel.).The second of the mentioned species occurs on all kinds of dung, especially horse, cattle and sheep, is widespread and probably cosmopolitan (Watling, Gregory 1987;Noordeloos 1999;Gminder 2003), but according to Kytövuori (1999), it is currently somewhat reverted in most areas due to the changes in the countryside living.It is assumed that diminishing and disappearance of woodland pastures and disappearing of horses in forestry and agricultural work may be the reason that, in regions characterised by the fairly higher elk density, P. semiglobata is rarer and replaced by P. alcis within forest communities.Nevertheless, in the case of north-eastern Poland this hypothesis is preliminary and should be tested in the future.
Microscopically the identification of P. alcis is very easy and more certain.In this case a confirmation is based on the basidospore size, the general shape of cheilocystidia, and the presence of chrysocystidia.The smaller and narrower spores (less than 8.5 μm wide) with a relatively large germ pore are sufficient distinctive in comparison with other members of the semiglobata-group, including P. semiglobata .Micromorphological features of the examined specimens are in good agreement with the previous descriptions of P. alcis (Kytövuori 1999;Noordeloos 2011), although it is worth emphasizing here that various authors have reported somewhat different measurements of given microcharacters (cf.Table 1).Nevertheless, we suppose that this insignificant discrepancy probably is attributable to a difference in sample size.
Since P. alcis is rather characteristic in substrate preference, it has probably not been much overlooked, but a kind of substrate may have caused less attention from macro-mycologists.Problems with simple -unambiguous recognition of decayed dung of elk may be also of a great importance.In our opinion, it is a real chance to find further even more rich localities of this agaric in the regions characterized by the relatively higher density of Alces ales (cf.Ratkiewicz 2011).Therefore, it appears especially reasonable to pay attention to P. alcis within the areas act as the crucial refuges and/or corridors for many rare macrofauna species, certainly including elk (e.g.The Biebrza Marshes; cf.Kujawa et al. 2012).Unlike in Mt Wierzejska, in the Wigierski National Park P. alcis seems not to be rare (Fig. 1).It seems, based on available data, that it should be classified in Poland at least as "vulnerable" and placed on the red list.It is to be hoped that future collectors will be able to extend the present sparse observations, so that this interesting species can be assigned its correct threat status in the Polish area.

Fig. 1 .
Fig. 1.Distribution of Protostropharia alcis in Poland (A), and in the Wigierski National Park (B): 1 -border of country, 2 -boundaries of the Park, 3 -new localities of the species, 4 -known localities of the species.

Table 1
Comparison of selected morphological features of Protostropharia alcis (Kytöv.)Redhead, Thorn & Malloch according to different studies