New records of the genus Lepiota for Iran, including two deadly poisonous species

INTRODUCTION

The genus Lepiota (Pers.: Fr.) Gray (Agaricaceae, Agaricales), comprises saprotroph agarics with scaly pileus, free gills, white spore print and stipe with ring or ring zone. About 400 Lepiota species have been reported from all over the world (Kirk et al. 2008). Some species of the genus contain amanitin toxin and are known as lethal poisonous. Because of the controversial taxonomy of toxic and non-toxic species, no Lepiota species is recommended as edible (Asef 2009, Sgambelluri et al. 2014). Up to now, 17 Lepiota species, L. acutesquamosa (Weinm.) P. Kumm., L. americana (Peck) Sacc., L. anthomyces (Berk. & Broome) Sacc., L. aspera (Pers.) Quél., L. brunnea Farl. & Burt, L. castanea Quél., L. cepaestipes(Sowerby) Sacc., L. clypeolarioidesRea, L. cristata (Bolt.) P. Kumm., L. felina (Pers.) P. Karst., L. helveola Bers., L. holospilota (Berk. & Broome) Sacc., L. leprica (Berk. & Broome) Sacc., L. lilacea Bres., L. metulaespora (Berk. & Broome) Sacc. , L. micropholis (Berk. & Broome) Sacc., L. naucina (Fr.) P. Kumm., L. roseoalba P. Henn., L. serena (Fr.) Sacc. and L. subalba Kühner ex P.D. Orton have been reported from Iran (Asef and Muradov 2012, Fallahyan 1973, Mohammadi Goltepeh 2002, Saber 1994, Saber & Esmaeili Taheri 2002, Saber & Zangeneh 2002).

Eight of the reported species, L. acutesquamosa, L. americana,L. asperaL. brunnea, L. cepaestipes, L. holospilota, L. naucina and L. serena have been transferred to genera Chlorophyllum, Echinoderma, Leucoagricus and Leucocoprinus as Echinoderma asperum (Pers.) Bon, Leucoagaricus americanus (Peck) Vellinga, Echinoderma asperum,Chlorophyllum brunneum (Farl. & Burt) Vellinga, Leucocoprinus cepistipes (Sowerby) Pat., Leucocoprinus holospilotus (Berk. & Broome) D.A. Reid, Leucoagaricusleucothites (Vittad.) Wasserand Leucoagaricus serenus (Fr.) Bon & Boiffard, respectively. The objective of this study was to introduce new records of the genus Lepiota for Iran.

MATERIALS AND METHODS

Fungal specimens used in this study were collected from northern forests of Iran during some fungal surveys. Specimens were studied in distilled water and Melzers reagent and were described based on the characters observed in fresh and dried basidiocarps. Microstructures were studied using an Olympus microscope and spore prints were obtained by placing pilei over sterile paper. All of the microstructures range was obtained by measuring about 30-40 structures. Specimens identified using Vellinga (2001), Hansen & Knudsen (1992), Knudsen & Vesterholt (2008) and Moser (1983). All of the collected samples were kept in the Fungus Collection of the Iranian Ministry of Jihad-e Agriculture (IRAN), located at the Iranian Research Institute of Plant Protection, Tehran, Iran.

RESULT AND DISCUSSION

Identification of collected samples of the genus Lepiota showed that three species are new for Iran mycobiota. Details of studied materials along with short description are as follows:

Lepiota brunneoincarnata Chodat & C. Martín, Bull. Soc. bot. Genève, 2 sér. 5: 222 (1889) (Fig. 1).

Pileus 2-5.5 cm, convex, then expanded and umbonate and finally depressed with age, whitish-pink covered by concentrical vinaceous-brown scales. Lamellae free, medium spaced, whitish. Stipe 2-6 × 0.5-1 cm, cylindrical, white above the inconspicuous ring, whitish-pink covered by brown scales below the ring zone. Spores 8-10.5 × 4-5 μm, elliptical to amygdaloid, smooth. Spore print white, cheilocystidia 20-40 × 5-10 μm, cylindrical to narrowly clavate, sometimes septate, pleurocystidia absent, pileipellis a trichoderm from cylindrical cells. Clamp connections present.

Specimens examined. IRAN, Gilan, Asalem to Khalkhal, on soil, 30 Sept. 2003, Asef & Sadeghi, IRAN 16229 F; Gilan, Gisom forest, on soil, 30 June 2005, Asef & Sadeghi, IRAN 16230 F.

Fig. 1. Lepiota brunneoincarnata. a. Spores — Scale bar = 5 µm); b. Basidium and cystidia — Scale bar = 10 µm; c. Pileipellis — Scale bar = 30 µm.

The species is characterised by pileus and scales color, size of spores and pileipellis structure. L. brunneoincarnata can cause fatal poisonings due to their content of amatoxins, such as α-amanitin,
β-amanitin, amanin, and amaninamide. Amatoxins are a group of bicyclic octapeptides produced by some species of mushrooms (Sgambelluri et al. 2014). There are various reports of poisoning and death by L. brunneoincarnata throughout the world, e.g. France, Spain, Tunisia and Turkey (Ben et al. 2009, Herráez et al. 2002, Kose et al. 2015, Varvenne et al. 2015). Lepiota brunneoincarnata has already been reported from all over the Europe and from temperate Asia in China, India, Pakistan and Turkey (Afyon & Yağiz 2004, Razaq et al. 2014, Vrinda et al. 2011).

Lepiota echinella Quél. & G.E. Bernard, Bull. Soc. mycol. Fr. 4: pl. 1, fig. 2 (1888) (Fig. 2).

Pileus 1.5-4.5 cm, convex to plane and slightly umbonate, whitish color covered by brown erect scales concentrated toward the center. Lamellae free, crowded, creamy whitish. Stipe 2-6 × 0.5-0.7 cm, cylindrical or clavate at base, pale brown, covered by white fibrils. Sometimes with a fibrillose ring zone. Spores 4.5-6.5 × 2.5-4 μm, elliptical, smooth. Spore print white, cheilocystidia 15-35 x 10-15 μm, lageniform, pileipellis of elongate cells intermixed with clavate cells.

Specimens examined. IRAN, Golestan, Gorgan, Rango Forest, on soil, 15 May 2011, Asef & Torabi, IRAN 15415 F.

Erected brown scales, size and shape of spores and intermixed pileipellis make L. echinella typical. Lepiota echinella is a widespread but rare species in Asia and Africa (Kosakyan et al. 2008) and has already been reported from European country such as Netherlands, Poland and Czech Republic (Vellinga, 2001, Wojewoda, 2003, Zelený, 2006).

Fig. 2. Lepiota echinella. a. Spores. — Scale bar= 1 µm); b. Cheilocystidia — Scale bar= 10 µm; c. Pileipellis — Scale bar= 10 µm.

Lepiota subincarnata J.E. Lange, Fl. Agaric. Danic. 5 (Taxon. Consp.): V (1940) (Fig. 3).

Pileus 1.5-5.5 cm across, convex, then expanded with umbonate disc, white to pinkishwhite covered by reddish brown to pinkish brown scales concentrated toward the center. Lamellae free, crowded, white to cream. Stipe 2-6 × 0.3-0.6 cm, cylindrical, broadened towards base, white to pinkish, surface smooth to scaly with fibrillose scales below the ring zone. Spores 5-7.5 × 3-4 μm, oblong ellipsoid to ovoid, some of the basidia with 2 spores, dextrinoid, spore print white. Cheilocystidia 15-40 × 6-12 μm, clavate. Pleurocystidia absent. Pileipellis a trichoderm with hyaline to light brown clavate elements. Clamp connection present.