Lamproderma ovoideoechinulatum Mar. Mey. & Poulain

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 : 192-193

Lamproderma ovoideoechinulatum Mar. Mey. & Poulain , in Poulain & Meyer (2005: 17). Fig. 14

Sporocarps in loose groups, stipitate, total height 1.76–2.52 mm (Figs A–C). Sporotheca ovoid, always higher than wide, base obtuse or broadly conical, more rarely slightly decurrent on the stalk, 1.30–1.64 mm high, 1.04–1.32 mm diam, with numerous, mostly blue green, but also with violet and yellow colour reflections, brownish at base ( Figs 14A–B ). Hypothallus well developed, red brown, continuous and connecting many sporocarps. Stalk 1/5 to 2/5 of the total sporocarp height, 0.36–0.96 mm long, black, tapering upwards ( Figs 14A–C ). Peridium persistent, thin, thicker only at base, dehiscing irregularly in large patches, with persistent colour reflections when spores are blown out, hyaline and smooth in transmitted light in upper part of sporotheca, pale red brown at the base of the sporotheca. Columella reaching about one-half of the sporotheca height, cylindrical or tapering upwards, often with membranous expansions at apex ( Fig. 14D ). Capillitium originating from the greater part of the columella, dense, rigid, brown with white extremities when spores are blown out, rusty brown, dark brown with hyaline extremities in transmitted light, with many anastomoses and many pointed ends ( Fig. 14D ). Spores in mass dark brown, blackish brown, dark brown in transmitted light, slightly paler at one side, globose 13.5–15.5(16) μm in total range, 14.77 ±0.5 μm on average ±SD (n = 60), covered with spines about 1 μm high ( Figs 14E–F ), baculate by SEM, baculae long and uneven at apices ( Figs 14G–H ).

Material examined:— USA. Tehama Co.: 3 miles E of Mineral, 5000 ft., on duff, 20 May 1967, DTK 6147 (as L. sauteri, UC 1408237!); 3 miles W of Child’s Meadows, 5200 ft., on bark, 20 May 1967, DTK 6223 (as L. sauteri, UC 1408283!).

Notes:— Lamproderma ovoideoechinulatum is a recently described species ( Poulain & Meyer 2005) that was not known to Kowalski (1970a), who apparently treated L. sauteri in a wider sense including specimens with ovoid sporothecae. Two of the specimens identified by Kowalski (1970a) as L. sauteri have clearly ovoid sporothecae with dark capillitium originating from the greater part of the columella ( Fig. 14D )—the character of L. ovoideoechinulatum . Since L. sauteri and L. ovoideum have similar spores ( Figs 14E–H , 19D–G ), Kowalski (1970a) who depreciated sporotheca shape and overestimated spore characteristics could not tell these two morphotypes apart. Lamproderma ovoideoechinulatum is known from Europe, North America and Asia ( Poulain et al. 2011).

Figures

FIGURE 14. Lamproderma ovoideoechinulatum Mar. Mey. & Poulain A–B. Sporocarps (note ovoid shape of sporotheca and numerous colour reflections). C. Open sporocarp (note brown capillitium). D. Columella and capillitium in transmitted light. E. Spores in transmitted light (edge view). F. Spores in transmitted light (top view). G. Spore by SEM. H. Details of spore ornamentation by SEM (note long baculae with uneven apices). Bars: A–C = 1 mm, D = 500 μm, E–G = 10 μm, H = 3 μm.A–B, D–H: coll. DTK 6147, C: coll. DTK 6223.

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.