Lamproderma maculatum Kowalski (1970a: 654)

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 : 190-191

Lamproderma maculatum Kowalski (1970a: 654) . Fig. 13

Sporocarps in large colonies, loosely arranged, stipitate, total height 1.14–1.82 mm ( Fig. 13A ). Sporotheca globose, 0.70–1.18 mm high, 0.64–1.10 mm diam, with numerous, blue and violet colour reflections, rarely without reflections and then blackish, covered with needle-like crystals, with well-visible depressed, dark brown patches, fusing into large areas at the base of sporotheca ( Fig. 13A ). Hypothallus well developed, red-brown, continuous and connecting many sporocarps. Stalk 1/4 to 1/2 of the total sporocarp height, 0.36–0.58 mm long, black ( Fig. 13A ). Peridium persistent, thin, dehiscing irregularly in large patches, hyaline with well-visible brown patches in transmitted light ( Fig. 13C ), dark brown at the base of sporotheca. Columella reaching about one-half of the sporotheca height, narrowly conical or only slightly expanded at apex. Capillitium originating from the upper part of the columella, dense, rigid, reddish brown when spores are blown out, dark brown with hyaline extremities in transmitted light, with many anastomoses forming small-meshed reticulum, with incrusting pigment ( Fig. 13B ). Spores in mass dark brown, blackish brown, dark brown in transmitted light, paler at one side, globose 12.5–15.5(16) μm in total range, 13.98 ±0.8 μm on average ±SD (n = 170), covered with low and densely arranged warts ( Figs 13D–E ), aculeate by SEM, ornamentation less than 0.5 μm high ( Figs 13F–G ).

Material examined:— USA. Tehama Co.: 3 miles W, of Child’s Meadows, 5200 ft., on bark, 20 May 1967, DTK 6200, (as L. maculatum, UC 1408239!, type); 3 miles E of Mineral, 5000 ft., on dead twig, 20 May 1967, DTK 6100 (as L. maculatum, UC 1408203!); Well’s Cabin Campground, 6300 ft., on dead twigs, 18 June 1966, DTK 3470, together with Meriderma sp. (as L. sauteri, UC 1408286!); Butte Co.: 4 miles E of Inskip, 5500 ft., on decayed twig, 23 April 1966, DTK 2813 (as L. maculatum, UC 1408205!); Siskiyou Co.: Mt. Shasta, 7600 ft., on dead twig, 25 July 1967, DTK 7396 (as L. maculatum, UC 1408215!); Mt. Rainer National Park, Bench Lake Trail, 4500 ft., on twigs, 13 June 1968, DTK 8664 (as L. maculatum, UC 1408214!); Shasta Co.: Lassen Volcanic National Park, near Summit Lake, 6700 ft., on twigs, 2 July 1967, DTK 6551, together with Meriderma sp. (as L. atrosporum, UC 1408251!).

Notes:—All studied specimens matched well Kowalski’s (1970a) description and they were confirmed to be L. maculatum . The species is characterized by peridium with brown, depressed patches ( Figs 13A, C ) and large, dark brown, densely warted spores ( Figs 13D–G ). Additionally, one collection of L. sauteri was found to represent L. maculatum , but it seems to be rather an oversight or a mistake than a result of differences in original treatment of L. maculatum by Kowalski (1970a), since he describes in detail the characters distinguishing the two species ( Kowalski 1970a). Lamproderma maculatum is the most similar to L. pseudomaculatum Mar. Mey. & Poulain that differs in more delicate and paler capillitium and slightly smaller spores ( Poulain et al. 2011). Lamproderma maculatum is known from Europe, North America, Asia, South America and Australia ( Stephenson et al. 2007b, Stephenson & Shadwick 2009, Poulain et al. 2011, Ronikier & Lado 2015).

Figures

FIGURE 13. Lamproderma maculatum Kowalski A. Sporocarps (note black depressed areas and needle-like crystals on the peridium surface). B. Details of capillitium in transmitted light. C. Peridium in transmitted light (note brown patches visible on the peridium). 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 = 1 mm, B, D–F = 10 μm, C = 100 μm, G = 3 μm. A–G: coll. DTK 3470.