Didymium annulisporum H.W. Keller & Schokn.

Baba, Hayri, Gündoğdu, Fatma & Sevindik, Mustafa, 2021, Myxomycetes biodiversity in Gaziantep Province (Turkey) with four new records, Phytotaxa 478 (1), pp. 105-118 : 109

Didymium annulisporum H.W. Keller & Schokn. ( Fig. 3 )

Myxocarps gregarious to scattered, sessile, primarily sporocarpous, 0.1–0.4 mm diam., subglobose to depressed, white, occasionally with straight or rarely branched plasmodiocarps 0.08–0.16 mm wide and up to 1.5 mm long; peridium appearing as a single, eggshell-like layer composed of a thin membranous, colourless layer charged with crystals, dehiscence usually basal; columella absent; capillitium arising mainly from and remaining attached to the base, consisting of sub-parallel, hyaline threads, 1 µm diam.; spores dark brown, subglobose, (9–)10(–11) µm diam., the surface uniformly covered by truncate processes, appearing echinulate with light microscopy.

Comments:— From a macroscopic point of view, Didymium annulisporum resembles the very common D. difforme . Fruiting in small groups or scattered, sometimes oval to elongated, up to 0.5 mm wide and up to 1 mm long, white. Peridium eggshell-like, smooth or sometimes with small wrinkles, consisting of two tightly connected layers. Microscopically the traces of D. difforme are larger, dark purple-brown and covered with very small warts. D. comatum also has a peridium that falls off completely as a lid, but has a capillitium consisting of very thin elastic threads. D. quitense has a scarce net-shaped capillitium and D. saturnus has yellow-brown fruiting bodies and spores that are densely covered with warts. D. trachysporum can also look like this but it has purplish brown spores lighter in colour on one side and no equatorial ring around the tracks. D. annulisporum capillitium consists of stiff, dark coloured threads, with interconnections, sometimes with thickening, ending in thinning, transparent, often dichotomously branched points. The wires run more or less parallel from the base to the top ( Neubert et al. 1995, Gotink et al. 2010).

Specimens examined:— Şahinbey, on leaves of walnut, Gündoğdu 17, on petri dishes, Gündoğdu 29; on bark, Zea mays, Gündoğdu 17; Nizip, on leaves, Gündoğdu 24; Dülükbaba Forest, on pine cones, Gündoğdu 66; Oğuzeli, on debris and leaves of walnut, Gündoğdu 6.

Records in Turkey:— Hadim and Taşkent districts ( Eroğlu & Kaşik 2013).

World distribution:— Algeria, Austria, Denmark, France, Germany, Netherlands, Ukraine, USA.

Figures

FIGURE 3. Didymium annulisporum. a. Sporocarps. b. Spores, capillitium and lime crystals.