Meriderma cribrarioides (Fr.) Mar. Mey. & Poulain, 2011

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 : 203

Meriderma cribrarioides (Fr.) Mar. Mey. & Poulain , in Poulain et al. (2011: 551). Fig. 22

Sporocarps scattered or in loose groups, stipitate, total height 1.32–2.64 mm ( Fig. 22A ). Sporotheca globose with rounded base, 0.74–1.30 mm high, 0.76–1.20 mm diam. Hypothallus, thick, rusty brown, pinkish brown, continuous and connecting many sporocarps. Stalk 1/3 to 1/2 of the total sporocarp height, 0.40–1.36 mm long, black, tapering upwards, often with membranous hypothallus remnants attached on one side ( Figs 22A–B ). Peridium evanescent, dehiscing in small patches, remaining only at the base of the sporotheca, black, iridescent, with silver and golden reflections under reflected light ( Figs 22A–B ), pale brown, smooth and transparent in transmitted light. Columella reaching about one-half of the sporotheca height, cylindrical to narrowly clavate ( Fig. 22B ). Capillitium moderately dense, black when spores are blown out, dark brown in transmitted light, with few to many anastomoses in peripheral part and with funnel-shaped ends ( Figs 22B–C ). Spores black in mass, moderately brown in transmitted light, slightly paler at one side, globose, (12)12.5–18(19) μm in total range, 14.66 ±1.5 μm on average ±SD (n = 240), covered with complete or slightly interrupted reticulum, banded-reticulate ( Figs 22D–E ), reticulum formed of low and perforated to high and almost complete bands, mostly without a perforated muri by SEM, ornamentation up to 2 μm high ( Figs 22F–G ).

Material examined:— USA. Tehama Co: 3 miles E of Mineral, 5000 ft., on dead twig, 20 May 1967, DTK 6105 (as L. cribrarioides, UC 1408204!); 5 miles W of Child’s Meadow, 5100 ft., 30 April 1966, DTK 2878, together with Lamproderma sp. (as L. cribrarioides, UC 1408224!); 6 miles S of Lassen Park, 5800 ft., on dead twigs, 27 April 1968, DTK 8285 (as L. cribrarioides, UC 1408207!); Siskiyou Co.: Mt. Shasta, 7600 ft., on dead twigs, 25 July 1967, DTK 7450 (as L. cribrarioides, UC 1408200!); Whatcom Co.: 16 miles E of Glacier, 4000 ft., on twigs, 20 June 1968, DTK 9077 (as L. cribrarioides, UC 1408217!); 15 June 1968, DTK 8779 (as L. cribrarioides, UC 1408218!); Lassen Park, near Summit Lake, 7000 ft., on dead twig, 26 July 1967, DTK 7484 (as L. cribrarioides, UC 1408208!); Mt. Rainer National Park, Bench Lake Trail, 4300 ft., on twigs, 10 June 1968, DTK 8413 (as L. cribrarioides, UC 1408229!);

Notes:—Most revised Kowalski’s (1970a) specimens of L. cribrarioides were confirmed to be this species, currently included in the genus Meriderma ( Poulain et al. 2011) . For further notes see comments at L. retirugisporum . Perforations in spore reticulation have been observed in all spores examined under SEM, also in those with the most regular and highest reticulation. Meriderma cribrarioides occurs in Europe ( Poulain et al. 2011).

Figures

FIGURE 22. Meriderma cribrarioides (Fr.) Mar. Mey. et Poulain A. Sporocarps. B. Open sporocarp. C. Funnel-shaped capillitium tip 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–F = 10 μm, G = 3 μm. A, C–G: coll. DTK 8285, B: coll. DTK 9077.