Lamproderma ovoideum Meylan (1932: 370)

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 : 194-195

Lamproderma ovoideum Meylan (1932: 370) . Fig. 15

Sporocarps in loose groups, stipitate, total height 1.28–1.72 mm ( Fig. 15A ). Sporotheca ovoid, usually higher than wide, base obtuse or broadly conical, 0.72–1.26 mm high, 0.72–1.10 mm diam, brown, only slightly iridescent with blue, violet and golden reflections ( Fig. 15A ). Hypothallus well developed, red brown, continuous and connecting many sporocarps. Stalk 1/4 to 4/9 of the total sporocarp height, 0.40–0.64 mm long black ( Figs 15A–B ). Peridium persistent, thin, thicker only at base, dehiscing irregularly in large patches, brown in transmitted light, inner surface rough. Columella reaching about one-half of the sporotheca height, cylindrical or tapering upwards ( Figs 15B–C ). 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 ( Figs 15B–C ). Spores in mass dark brown, blackish brown, moderately brown in transmitted light, slightly paler at one side, globose (12)13.0–15 μm in total range, 13.90 ±0.7 μm on average ±SD (n = 30), covered with spines ( Figs 15D–E ), baculate by SEM, baculae about 1 μm high, with slightly irregular tips ( Figs 15F–G ).

Material examined:— USA. Mt. Rainer Nat. Park , Bench Lake Trail , 4500 ft., on twigs, 10 June 1968, DTK 8401 (as L. carestiae, UC 1408273!) .

Notes:— Kowalski (1970a) did not recognize L. ovoideum as a separate taxon, but considered it to be conspecific with L. sauteri . Interestingly, however, none of the revised specimens of L. sauteri turned out to be L. ovoideum . Only one specimen of typical L. ovoideum was found in the examined material and this collection was originally identified as L. carestiae . Lamproderma carestiae was considered by Kowalski (1970a) as including L. ovoideum var. cucumer Meyl. , currently treated at a species level as L. cucumer (Meyl.) Nowotny & H. Neubert. Lamproderma ovoideum occurs in Europe, North and South Americas, Asia, Australia and New Zealand ( Stephenson et al. 1992, Stephenson & Johnston 2003, Stephenson et al. 2007a, b, Stephenson & Shadwick 2009, Poulain et al. 2011, Ronikier & Lado 2015).

Figures

FIGURE 15. Lamproderma ovoideum Meyl. A. Sporocarps (note ovoid shape of sporotheca and domination of brown colours). B. Open sporocarp (note brown capillitium).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–G: coll. DTK 8401.