Lamproderma pseudomaculatum Mar. Mey. & Poulain, Documents Mycologiques

Yatsiuk, Iryna & Leontyev, Dmitry, 2020, Two species of nivicolous myxomycetes that formed fruiting bodies during three spring seasons in the lowlands of the Eastern Ukraine, Phytotaxa 437 (3), pp. 147-155 : 149-151

Lamproderma pseudomaculatum Mar. Mey. & Poulain, Documents Mycologiques 24 (96): 7 (1995) — Fig. 3 .

Description:— Sporocarps stalked, occasionally sessile, (0.5) 1.2–1.3 (1.8) mm in total height (N=125). Sporothecae globose to ovoid, (0.4) 0.7–0.8 (1.2) × (0.4) 0.8–0.9 (1.4) mm diam. (N=125). Stalk, if present, (0.1) 0.4–0.5 (0.9) mm (N=116) in height, black, extending towards the base, often covered with reddish membranous cover. Hypothallus membranous, reddish-brown to brown, shiny, often common for groups of sporocarps. Peridium membranous, iridescent with purple, blue, bronze colors, translucent in transmitted light, mottled with numerous dark spots (maculae), blackish to pale brown in transmitted light. Occasionally peridium is sprinkled with needle-like lime crystals (splinters), scarce or rather abundant. Columella reddish-brown to dark brown in transmitted light, reaching the half of the sporotheca. Capillitium brown at the base, pale pinkish to almost white near the ends. Spores black in mass, violet-brown in transmitted light, with a pale area, covering nearly 1/3 of the spore surface, globose to subglobose, warted as observed under the light microscope, (9.7) 11.8–12.2 (15.6) µm (N=140). SEM shows ornamentation of warts and baculae, merged into ridges or batches of irregular shape. In specimen CWU-MS-404, the episporium is prominently detached on one side.

Habitat:— 1, on living leaves of Carex pilosa , dead leaves of Acer platanoides , Quercus borealis , Q. robur , twiglets of Q. borealis , Fraxinus excelsior ; 2, on living leaves of C. pilosa , dead leaves of Q. robur , twiglets of deciduous trees; 3, on dead Populus tremula twiglets 0.5 cm in diameter.

Specimens examined:— CWU-MS-372, CWU-MS-373, CWU-MS-374, CWU-MS-375, CWU-MS-402, CWU- MS-432, CWU-MS-433, CWU-MS-404.

DNA sequences:— GenBank accession numbers for the partial sequence of the 5ʹ end of 18S rDNA: MN310316 (CWU-MS-402), MN310317 (CWU-MS-404).

Notes:— Lamproderma pseudomaculatum can be distinguished from the morphologically similar L. echinosporum Meylan (1924: 240) by its warted spores, in contrast to spinose ones in the latter species. The main difference from another similar species, L. maculatum Kowalski (1970: 654) , is the paler capillitium with whitish ends, instead of dark brown ones in L. maculatum .

The studied specimens demonstrate a strong variability in macroscopic features, including tints of peridium iridescense, varying from bronze and violet ( Fig. 3 C ) to bright blue ( Fig. 3 A–B ). Another feature, extremely variable in this species, is the presence of maculae, which can be either pronounced and nicely visible under a stereomicroscope ( Fig. 3A ) or very pale and hardly recognizable even in transmitted light. The third character with considerable variability is the needle-shaped calcium oxalate crystals, which may be either very abundant ( Fig. 3 B ) or totally absent ( Fig. 3 C ).

Lamproderma aff. pulchellum Meyl. , Bulletin de la Société Vaudoise des Sciences Naturelles 57: 369 (1932) — Fig 4 .

Description:— Sporocarps sessile or short-stalked, (0.5) 0.9–1.0 (1.5) mm in total height (N = 50). Sporothecae globose, ellipsoid or ovoid, (0.4) 0.7–0.8 (1.2) × (0.5) 0.8–0.9 (1.4) mm diam. (N = 50). Stalk, if present, (0.05) 0.2–0.3 (0.6) mm (N = 39) in height, reddish-brown, membranous, extending towards the base. Hypothallus membranous, reddish-brown, shiny. Peridium membranous, iridescent with light- to dark blue as dominant colors, bearing ring-like reddish and yellowish zones; translucent in transmitted light, sometimes bearing small dark spots. Columella reddish-brown to black, reaching about half the height of the sporothecae. Capillitium dense, pale pinkish-brown at the base and pale pink to almost white at the ends, as observed in transmitted light. Spores dark brown in mass, violet-brown in transmitted light, with a pale area, covering less than ¼ of the spore surface, globose to subglobose, warted as observed under the light microscope, (9.8) 11.2–11.5 (12.7) µm (N = 50). SEM shows irregular ornamentation of solitary or grouped, but not merged warts, spinules or baculae.

Habitat:— 1, on living leaves of Carex pilosa ; 2, on twiglets of deciduous trees, dead leaves of Quercus robur and Corylus avellana .

Specimens examined:— CWU-MS-371, CWU-MS-403, CWU-MS-408, CWU-MS-410, CWU-MS-414, CWU- MS-416.

Sequences:— GenBank accession number for the partial sequence of the 5ʹ end of 18S rDNA MN310318 (CWU- MS-403).

Notes:— Zones of reddish and yellowish tints on the peridium, resembling those of L. zonatum , distinguish our collections from the original description of L. pulchellum Meylan (1932: 369) .

Figures

FIGURE 3. Lamproderma pseudomaculatum Mar.Mey.et Poulain.A–D. Sporocarps. E, F. Capillitium.G. Peridium (arrowheads indicate maculae). H, I. Spores.

FIGURE 4. Lamproderma aff. pulchellum Meyl. A–D. Sporocarps. E, F. Capillitium. G. Peridium and spores. H, I. Spores.