Lamproderma columbinum (Pers.) Rostaf.

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 : 185-186

Lamproderma columbinum (Pers.) Rostaf. in Fuckel (1873: 69). Fig. 9

Sporocarps scattered, stipitate, total height 2.44–3.94 mm. Sporotheca ovoid to shortly cylindrical, 0.54–1.00 mm high, 0.44–0.80 mm diam ( Fig. 9A ). Hypothallus thick at stalk base but small, red brown, discoid. Stalk very long, 2/3 to 4/5 of the total sporocarp height, 1.66–3.20 mm long, black, shining ( Figs 9A–B ). Peridium persistent, dehiscing in patches, surface rough, with blue and violet colour reflections, pale brown and rough from pale brownish pigment in transmitted light. Columella reaching about 2/3 of the sporotheca height, massive, narrowly conical to cylindrical ( Fig. 9C ). Capillitium dense, pale when spores are blown out, brownish at base and white at extremities, pale in transmitted light, slightly darker near columella ( Figs 9B–C ), becoming gradually paler toward extremities, branches delicate and thin, near the columella about 1–2(3) μm wide, dichotomously branched, with few anastomoses in central part and many anastomoses at extremities, forming small-meshed net, rough from brownish pigment, in peripheral part threads about 0.5–1 μm wide, with zebra-like pattern from discontinuous incrusting pigment. Spores dark brown in mass, pale grey brown in transmitted light, uniformly coloured, globose to subglobose, 11.5–14(14.5) μm in total range, 12.87 ±0.7 μm on average ±SD (n = 120), covered with irregularly distributed warts 0.5–1 μm high ( Figs 9D–E ), baculate by SEM, baculae cylindrical ( Figs 9F–G ).

Material examined:— USA. Mendocino Co.: MacKerricher Beach State Park, on decayed wood [covered with mosses], 25 January 1967, DTK 4826 (as L. columbinum, UC 1408267!), DTK 4824 (as L. columbinum, UC 1408223!); 7 April 1968, DTK 8055 (as L. columbinum, UC 1408228!); on bark [covered with mosses], 8 April 1968, DTK 8087 (as L. columbinum, UC 1408222!).

Notes:— Lamproderma columbinum is very characteristic species due to the long but massive stalk, small sporotheca and thick columella. All specimens identified by Kowalski (1970a) as L. columbinum were confirmed to be this species. The species is cosmopolitan ( Poulain et al. 2011).

Figures

FIGURE 9. Lamproderma columbinum (Pers.) Rostaf. A. Sporocarp (note relatively massive stalk and small sporotheca). B. Open sporocarp with visible whitish capillitium. C. Columella and capillitium in transmitted light (note massive columella). 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 = 200 μm, D–F = 10 μm, G = 3 μm. A, D–E: coll. DTK 4824, B, F–G: coll. DTK 4826, C: coll. DTK 8055.