Lamproderma scintillans (Berk. & Broome) Morgan (1894: 131)

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 : 199-200

Lamproderma scintillans (Berk. & Broome) Morgan (1894: 131) . Fig. 20

Sporocarps scattered, stipitate, total height (0.70)0.78–1.22(1.38) mm ( Figs 20A–B ). Sporotheca globose or nearly globose (almost always wider than high), (0.30) 0.34–0.60 mm high, (0.34) 0.36–0.64 mm diam, blue, violet, or golden, or with mixture of these colours, shining ( Figs 20A–B ). Hypothallus red brown, discoid. Stalk short to long from 3/8 to 2/3 of the total sporocarp height, (0.26)0.30–0.86(0.96) mm long, black, shining ( Figs 20A–C ), usually cylindrical, sometimes slightly enlarged downwards. Peridium persistent, but soon dehiscing in large patches, so many sporangia are without peridium remnants, surface rough, blue, violet and golden colours well visible also on fallen peridium patches or when spores are blown out, peridium thin, hyaline and smooth in the upper part of sporotheca in transmitted light, very pale orange at the base of sporotheca. Columella reaching less than one-half of the sporotheca height, usually about 1/3, cylindrical, usually with an obtuse or truncate apex, more rarely slightly enlarged ( Fig. 20C ). Capillitium originating from the apical part of columella, moderately dense or loose, bi-coloured when spores are blown out white near the columella and brown in major outer part as observed in reflected light, hyaline or pale orange at the distance of (10)30–60(100) μm near the columella in transmitted light, red brown to dark brown in major outer part, threads straight to slightly flexuous, radially dichotomously branched, in central part smooth and with few anastomoses, in peripheral part smooth or with occasional to many nodules and with few to many anastomoses ( Figs 20C–D ). Spores brown in mass, pale brown in transmitted light, uniformly coloured or slightly paler at one side, globose, (6.5)7–10(10.5) μm in total range, 8.28 ±0.7 μm on average ±SD (n = 240), covered with loosely and perfectly regularly distributed spines ( Figs 20E–F ), broadly conical wih warted apices by SEM ( Figs 20G–H ).

Material examined:— USA. Butte Co.: Lower Bidwell Park, Chice, on decayed bark, 10 December 1966, DTK 4173 (as L. scintillans, UC 1408243!); Butte Creek & Skyway, on decayed twigs, 16 December 1966, DTK 4223 (as L. scintillans, UC 1408241!); U.S. 99 & Butte Creek, on plant debris, 9 December 1966, DTK 4093, together with Diacheopsis sp. (as L. scintillans, UC 1408231!); Glenn Co.: 13 miles S. of Hamilton City, on decayed wood, 29 December 1966, DTK 4519 (as L. scintillans, UC 1408265!); on decayed bark, 14 January 1967, DTK 4777 (as L. scintillans, UC 1408261!); DTK 4731, together with Comatricha sp. and Didymium sp. (as L. scintillans, UC 1408209!); Marin Co.: Tomales Bay State Park, on plant debris, 28 January 1967, DTK 5020 (as L. scintillans, UC 1408260!); Tehama Co.: Woodson Bridge State Park, on decayed leaves, 11 February 1967, DTK 5361, together with Badhamia sp. and Didymium sp. (as L. scintillans, UC 1408240!).

Notes:— Lamproderma scintillans is interpreted by Kowalski (1970a) in its present sense: as non-nivicolous species with capillitial threads much paler, often hyaline near the columella and brown at some distance from the columella ( Fig. 20D ), and with spores covered with perfectly regularly distributed broadly conical, dark brown spines ( Figs 20E–H ). The species is usually long-stalked (e.g. Poulain et al. 2011), but in the Kowalski’s material I found it to be variable, from short stalked (3/8 of the total sporocarp height; from 0.26 mm) to long stalked (2/3 of the total sporocarp height; up to 0.96 mm). All specimens identified as L. scintillans by Kowalski (1970a) was confirmed to belong to this species. Due to the characteristic spore ornamentation and bi-coloured capillitium it is one of the most easily identified species from the genus. It is cosmopolitan in distribution ( Poulain et al. 2011).

Figures

FIGURE 20. Lamproderma scintillans (Berk. & Broome) Morgan A–B. Sporocarps. C. Open sporocarp. D. Details of columella and capillitium in transmitted light (note hyaline capillitium threads near columella). 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. Bars: A–C = 500 μm, D = 100 μm, E–G = 10 μm, H = 3 μm. A: coll. DTK 5020, B–F: coll. DTK 4223, G–H: coll. DTK 4777.