Lamproderma arcyrioides (Sommerf.) Rostafiński (1874: 206)

Ronikier, Anna, 2022, Revision of the Donald T. Kowalski’s collections of Lamproderma (Myxomycetes, Amoebozoa) reveals twice higher species diversity, Phytotaxa 531 (3), pp. 175-210 : 180

Lamproderma arcyrioides (Sommerf.) Rostafiński (1874: 206) . Fig. 5

Sporocarps in loose groups, stipitate, total height 1.44–2.26 mm. Sporotheca globose or subglobose, 0.82–1.40 mm high, 0.84–1.56 mm diam. Hypothallus red brown, discoid or continuous under several sporocarps. Stalk moderately long, 2/7 to 1/2, usually about 1/2, of the total sporocarp height, 0.56–1.12 mm long, black, shining. Peridium persistent, dehiscing in large patches, surface smooth, strongly shining, covered with needle-like crystals, with blue, violet, green and yellow reflections ( Fig. 5A ) also when spores are blown out, pale brown and rough from brownish pigment in transmitted light, darker at sporotheca base. Columella reaching about one-half of the sporotheca height, narrow, cylindrical ( Fig. 5C ). Capillitium originating from the greater part of the columella, radiating, moderately dense, brown with white extremities when spores are blown out, rusty brown in transmitted light, with many anastomoses especially in peripheral part, extremities paler ( Figs 5B–C ). Spores in mass dark brown, blackish brown, moderately pale brown in transmitted light, slightly darker at one side, globose 9–11(11.5) μm in total range, 10.12 ±0.6 μm on average ±SD (n = 180), covered with densely arranged warts ( Figs 5D–E ), baculate by SEM, baculae of uneven surface ( Figs 5F–G ).

Material examined:— USA. Tehama Co.: 3 miles E of Mineral, 5500 ft., on decaying twigs, 30 April 1966, DTK 2913 (as L. carestiae, UC 1408227!); Lassen Park, 6 miles S of Lassen Park, 5800 ft., on dead twigs, 27 April 1968, DTK 8286, together with Lamproderma echinosporum (as L. echinosporum, UC 1408254!); 2 miles S of Lassen Park, 6000 ft., on decayed wood, 21 May 1966, DTK 3060 (as L. carestiae, UC 1408210!); Butte Co.: 4 miles above Stirling City, 4000 ft., on dead wood, 27 May 1967, DTK 6247 (as L. carestiae, UC 1408245!); Siskiyou Co.: Mt. Shasta, 7200 ft., on dead wood, 4 July 1967, DTK 6682 (as L. carestiae, UC 1408270!); Shasta Co.: Lassen Park, Hat Lake, 6500 ft., on leaves, 1 July 1967, DTK 6510 (as L. carestiae, UC 1408242!); Crater Lake National Park, Garbage Dump, 6400 ft., on dead wood, 8 July 1967, DTK 6877 (as L. carestiae, UC 1408264!).

Notes:—All specimens identified by Kowalski (1970a) as L. arcyrioides turned out to be L. pulveratum (see comment to this species below), while all specimens identified by me as L. arcyrioides were identified by Kowalski (1970a) as L. carestiae . Lamproderma carestiae was defined by Kowalski (1970a) as a species with short stipe, dark brown capillitium, colourless only at the extremities, and densely spinulose, uniformly coloured spores 10–12 μm, while L. arcyrioides was defined as a species with distinctly pale capillitium tips and minutely warted spores 8–11 μm in diam. Interestingly, Kowalski (1970a) believed that L. arcyrioides and L. carestiae frequently interbreed and that the separation of these two species is difficult. Apparently, L. caresiae ss. Kowalski (1970a) is a scpecies complex including L. arcyrioides , L. ovoideum , L. sauteri var. atrogriseum and L. aff. ovoideum ( Fig. 1 ). For further information, see comments under these species. Lamproderma arcyrioides occurs in Europe, North America and probably Asia ( Poulain et al. 2011).

Figures

FIGURE 1. List of species identified: left column—original identifications by Kowalski (1970a), right column—updated list of species after revision of examined collections.Green—identification of all specimens confirmed,yellow—identificationof all specimens corrected, blue—some misidentifications noted (the species present before and after revision, but based on different collections), grey—collection too scanty for a proper identification to species. Dotted line—species noted as admixture to another species.

FIGURE 5. Lamproderma arcyrioides (Sommerf.) Rostaf. A. Sporocarp with irridescent peridium and needle-like crystals. B. Open sporocarp with visible whitish capillitium. C. Columella and capillitium in transmitted light. D. Spores in transmitted light (edge view). E. Spores in transmitted light (top view). F. Spores by SEM. G. Details of spore ornamentation by SEM. Bars: A–B = 1 mm, C = 500 μm, D–F = 10 μm, G = 3 μm. A, D–E: coll. DTK 2913, B–C: coll. DTK 6682, F–G: coll. DTK 6247.