Lamproderma sauteri var. atrogriseum Meylan (1932: 366)

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 : 199

Lamproderma sauteri var. atrogriseum Meylan (1932: 366) . Fig. 19

Sporocarps scattered, stipitate, total height 1.38–2.64 mm ( Fig. 19A ). Sporotheca globose, with flat base, usually wider than high, 0.74–1.24 mm high, 0.84–1.36 mm diam, grey, silvery grey, shining, with few colour reflections, rusty brownish at base ( Figs 19A–B ). Hypothallus well developed, orange brown, discoid. Stalk about one-half of the total sporocarp height, exceptionally longer, 0.56–1.54 mm long, red brown ro black, tapering upwards ( Figs 19A–B ). Peridium long persistent, remaining for a long time at lower half of sporotheca, not brittle, dehiscing irregularly in large patches from apex, watery white when spores are blown out, pale orange in the upper part of sporotheca in transmitted light, orange at the base of sporotheca, smooth ( Figs 19B–C ). Columella reaching about one-half of the sporotheca height, cylindrical or tapering toward apex, often with membranous expansions at apex ( Fig. 19C ). Capillitium originating from the apical part of columella, not dense, not rigid, delicate, orange to pale rusty brown when spores are blown out, tips white, orange with hyaline to almost hyaline extremities in transmitted light, dichotomously branched, with few anastomoses in central part and more connections in peripheral part ( Figs 19B–C ). Spores very dark brown in mass, dark brown in transmitted light, darker at one side, globose (13)13.5–16(16.5) μm in total range, 14.92 ±0.7 μm on average ±SD (n = 90), covered with irregularly distributed, isolated spines about 1 μm high ( Figs 19D–E ), spines slender and either pointed or divided into several finger-like outgrowths by SEM ( Figs 19F–G ).

Material examined:— USA. Olympic National Park, Hurricane Ridge, 5200 ft., on living twigs, 14 July 1967, DTK 7073 (as L. sauteri, UC 1408259!); DTK 7094 (as L. sauteri, UC 1408248!); DTK 7145 (as L. sauteri, UC 1408225!); DTK 7116 (as L. carestiae, UC 1408247!); Olympic National Park, 2 mi. below Hurricane Ridge, 4800 ft., on twigs, 22 June 1968, DTK 9177 (as L. sauteri, UC 1408285!).

Notes:— Kowalski (1970a) treated L. sauteri in a wider sense, including L. ovoideum . In the studied material, five of ten specimens identified by Kowalski (1970a) as L. sauteri have been confirmed. However, all of them had grey peridium only slightly iridescent—a character of var. atrogriseum and none of the examined specimens represented typical variety. Lamproderma sauteri is a cosmopolitan myxomycete ( Poulain et al. 2011).

Figures

FIGURE 19. Lamproderma sauteri var. atrogriseum Meyl.A. Sporocarps. B. Open sporocarp. C. Columella and capillitium in transmitted light. D. Spores in transmitted light (edge view). E. Spores in transmitted light (top view). F. Spore 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, C: coll. DTK 7073, B, F–G: coll. DTK 7116, D–E: coll. DTK 7145.