Licea nemotatarica Sadykov, 2024

Sadykov, Ruslan E. & Potapov, Kim O., 2024, Licea nemotatarica sp. nov. - a corticolous myxomycete from northern nemoral border of Eastern European boreal ecotone, Phytotaxa 668 (1), pp. 108-116 : 110-114

Licea nemotatarica Sadykov sp. nov. ( Figs 2 , 3 )

MycoBank number: MB855409

Etymology:— from Latin “nemoralis” and “ Tatarstan ” as one of the aboriginal dominant corticolous species in Eastern European northern border of nemoral zone located in Western Tatarstan.

Holotype:— RS900239, RUSSIA. RT, Verkhneuslon district: ravine broadleaved wet associations of Quercus robur , Tilia cordata , Acer platanoides , Ulmus spp. , Populus tremula in tree layer, Asarum europeum , Equisetum spp. , Mercurialis parennis in herbs, on grey soils on carbonate deposits to the east of Vveden sloboda village. 55.765080°N, 48.739150°E. Appeared at 95 th day in moist chambers, on bark of T. cordata . Substrate collected 5 Aug. 2022 by R. E. Sadykov.

Sporocarps separate, in groups of three to ten, deeply sessile, spherical, 210–340(–540) µm diam., 150–200 µm high ( Figs 2A–D , 3A, B, E–G ). Peridium double, layers easily separated ( Fig. 2I ); outer layer thick, cartilaginous, dull black, forming a rugose relief pattern of elongated furrows (23–31 µm high) ( Figs 2C, D , mostly laid down along lines, and consisting of spherical granular material 6–15 µm diam. ( Fig. 2H ); inner layer thin, membranous, richly black, smooth, shiny ( Fig. 2I, K ). In the early stages of sporocarp formation, the outer peridium is ochre, the inner one pale yellow ( Fig. 2C ). Peridium dehisces along the lines drawn inside the sporocarp (3.6–4 µm high) into plates ( Fig. 2D, E, G ). Number of plates varies from five to nine. The dehiscence line is darker than the whole peridium ( Fig. 2J ), consists of wavy thickenings ( Fig. 2F ), which form a plicate adherence to the inner peridium ( Fig. 2K ). Spores free, pear-green, greenish-silver ( Fig. 2E ), golden-green ( Fig. 3C ) in mass, light pale green to light golden-green ( Figs 2F , 3D, I, J ) in transmitted light ( TL), thin-walled, smooth, 8.6–9.5(–10.1) µm diam. ( Fig. 2F, G ). Hypotallus absent, protoplasmodium from dull white in first stages to yellow in next stages.

Macrohabitat:— deep, wet carbonate ravines, humid platen forest areas with Quercus robur , Tilia cordata , Acer platanoides , Ulmus spp. , Populus tremula in tree layer, Asarum europeum , Equisetum spp. , Mercurialis parennis in herbs.

Microhabitat:— well-decayed (cultivation day 80–270) bark of previously living Tilia cordata , Acer platanoides , Quercus robur , Populus tremula in mcc, pH 7–7.8

Distribution:— northern border of Eastern Europe broadleaf area in Western Tatarstan ( Fig. 4).

Additional specimens examined:— RS900322 – same locality as holotype, but appearance at 120 th day. RS900323 – same locality as holotype, but appearance on 160 th day on bark of A. platanoides . RS900324 – same locality as holotype, but appearance on 180 th day on bark of A. platanoides . RS900326, RS900327 – LOC 4, appeared from day 120 to 200 in mcc on bark of Q. robur . RS900328 – LOC 2, appeared on 140 th day in mcc on bark of Q. robur . RS900329 – LOC 3, appeared from day 220 to 270 in mcc on bark of P. tremula . RS900330, RS900331 – LOC 5, appeared from day 80 to 180 in mcc on bark of Q. robur .

Morphological comparison of L. nemotatarica with similar species are presented in table 1. The functional group is formed on a number of some similar features, such as comparatively large sporocarps; dark double-layered peridium, dehiscence into plates along performed lines with relief adhesion mechanism; smooth light spores; inhabiting on bark of living trees.

Notes:— Licea tuberculata and L. nigromarginata should be considered the most similar to L. nemotatarica , being united by the presence of a pattern of granular material on the surface of the peridium, in addition to the unifying factors already mentioned. However, L. nemotatarica differs from L. tuberculata in the colour of the spores (greenish vs. pale brown), in the pattern of the dehiscence line (wavy vs smooth), in the form of the sporocarps (deeply sessile vs. short-stalked) and in the inclusions of the outer peridium (light tubercles vs. dark furrows) ( Martin 1957). L. nemotatarica differs from the only once recorded L. nigromarginata , which probably has a similar striated pattern on the surface of the peridium, by a much smaller spore size (8.6–9.5 µm vs. 13–15 µm); by spore colour (pale green and golden green vs. pale brown); by a pattern of dehiscence lines (wavy vs. dotted); by habitat (bark of deciduous trees in the nemoral zone of European Russia vs. bark of conifer in the high mountain boreal zone of the Indian Himalayas); and by a more complicated relief, multi-row cartilaginous pattern of the outer peridium. Otherwise, a clear picture emerges of species preference for Quercus bark over Acer , Tilia , Populus ( Fig. 4) under the same cultivation conditions and similar hydrogen concentration in microhabitats.

Figures

FIGURE 2. Licea nemotatarica holotype. A–B. Well-formed sporocarp. C. Young sporocarp. D. Sporocarp in SEM. E. Spore mass. F. Spores in TL. G. Spores in SEM. H. Dehiscence line on outer peridium in SEM. I. Two layers of peridium in TL. J. Border of dehiscence line in TL. K. Dehiscence line on inner peridium in SEM. Bars: A–E = 100 µm, F–K = 10 µm.

FIGURE 3. Licea nemotatarica. A–D. From LOC 2; E–J. From LOC 4. A, B, E, F, G. Sporocarps in habit. C. Spores in mass. D, I, J. Spores in TL. H. Double layered peridium in TL. Bars: A = 300 µm, B, C, E–G = 200 µm, D, H, I, J = 10 µm.