Addendum to the mycobiota of smut fungi in Poland

The paper presents new records of three rare species of smut fungi in Poland. Anthracoidea buxbaumii was collected in new localities, A. caricis collected on Carex montana is a new fungus/host combination in Poland, and Urocystis ranunculiauricomi was found in the country after almost 50 years.


Introduction
Smut fungi (Ustilaginomycotina) are multicellular organisms characteristic by their dark, thick-walled, and dust-like teliospores.Smuts parasitize flowering plants, including many economically important hosts like maize, barley, wheat, oats, and forage grasses.
Detailed data about the distribution of smut fungi in Poland are summarized in the monograph by Kochman and Majewski [1] and in A preliminary checklist of micromycetes in Poland [2].Articles presenting data about the occurrence of this group in the country were published by Chlebicki [3], Piątek and Mułenko [4], Ruszkiewicz et al. [5], and Lutz and Piątek [6].Anthracoidea species are widely distributed in the temperate and subarctic regions of the Northern Hemisphere and the highland regions of the Southern Hemisphere.Currently, this genus is represented by approximately 112 species and this number is supposed to increase [7][8][9][10].The representatives of Urocystis are cosmopolitan and occur worldwide.Vanky [11] has recorded as many as 162 species in this genus.
The aim of this paper is to present new records of the distribution of some rare smut fungal species from Poland, i.e., Anthracoidea buxbaumii Kukkonen, A. caricis (Pers.)Bref., and Urocystis ranunculi-auricomi (Liro) Zundel.

Anthracoidea buxbaumii Kukkonen
Sori globose in the ovaries, usually scattered in the inflorescence, rarely: almost all ovaries infected (Fig. 1d).Spores dark reddish brown, flattened, in plane view broadly elliptical, ovate or irregular, 14-22(-24) × 20-26(-28) µm; wall 1-3.5 µm thick, with 1-3 indistinct internal swellings, without protuberances and light-refractive areas, minutely verruculose.Notes.In all the localities mentioned above, the host plants were heavily infected.Probably in the Polish part of the Polesie region, A. buxbaumii can be considered a relatively frequent species.Two localities in Poland situated in this area been published so far: Anthracoidea buxbaumii was found on C. buxbaumii in Bagno Serebryskie Reserve near Chełm town (GE 34) and on C. hartmanii Cajander in the Bagno Bubnów swamp (GE 12) in the Poleski National Park [4,14] (Fig. 2).The parasite forms spore clusters on female inflorescences of C. buxbaumii and C. hartmanii sedges.These plants represent rare taxa in Poland and occur in scattered localities over the country.Previously, they were regarded as an aggregate unit [15].Currently, accurate data on their occurrence as separate species have been presented by Sotek [16,17] and Gierczyk and Soboń [18].Both sedge species occur in peat bogs, i.e., habitats that are decreasing due to the reduced water level.Carex buxbaumii is included in the list of endangered taxa in Poland [19], which has been proposed to include C. hartmanii as well [17].In the regional list concerning the Polesie and Lublin regions, C. buxbaumii agg. is specified as a vulnerable species [20,21].Detailed data on the distribution of A. buxbaumii worldwide are presented in the paper by Piątek and Mułenko [4].
Sori black, globose in ovaries.Spores middle to dark reddish brown, flattened, in plane view subcircular, angular, or irregular, 16-19(-20) × 18-24 µm; wall 1.5-3 µm thick, the thickest at the angles, with 1-3 indistinct internal swellings, minutely verruculose; besides warts (0.2-0.3 µm high), minute papillae are visible in SEM (Fig. 1a,b).Notes.Anthracoidea caricis is one the most common species of Anthracoidea in Poland.Until now, it has been collected only on C. pilulifera -data on C. montana [1,2] should be referred to Ukraine (Pokucie Carpathians).This is first collection of the species on C. montana in Poland.The general distribution of this species ranges across the Northern Hemisphere [11].

Fig. 1
Fig. 1 Infected host plants and spores of the presented species.a,b Anthracoidea caricis on Carex montana.c,e,f Urocystis ranunculi-auricomi on Ranunculus auricomus (the white circle indicates an infected leaf).d Anthracoidea buxbaumii on Carex buxbaumii.