Heterotrichia insignis

Arcyria stipata sporophores are crowded, deformed from mutual compression, sporophores are red with lavender or rose tints and dry with a reddish brown hue.

It is found throughout the year on dead wood of coniferous and deciduous trees.

Diagnostic features. The almost pseudoaethalial habit, persistent peridium and copper colour make this species distinctive.

Sporocarps sessile or short-stalked, erect or ± superimposed and then subsessile, very densely crowded and (in large colonies) appressed, often resembling a pseudoaethalium, shining coppery pink, or copper to reddish ochraceous in the fresh state, metallic, often with lavender or rose tints, browning with age, 0·8–3 mm high.

Hypothallus shared, membranous, dark brown, confluent.

Stalk very short, 0·1–1·5 mm tall, often appearing to be absent, red-brown or dark brown, filled with round cells c. 13 μm diam.

Sporangia ± cylindrical, erect or curved, 0·8–1 × 0·5–0·8 mm, with a ± deep calyculus which is smooth or decorated with very fine papillae sometimes arranged in lines.

Peridium, in separate sporothecae, evanescent above and leaving a shallow cup, persistent in pseudoaethaliate forms and then splitting into lobes, persistent, shining, often iridescent, red with copper reflexions.

Capillitium loosely attached at the base and easily blown away, the upper part often breaking away with the peridium, forming a loose and rather lax net, somewhat elastic, the tubules 2·5–5 μm diam., bearing 3 or 4 spirals, these sometimes intermixed with spines, cogs, half-rings or occasional rings and partial reticulations, the whole ornamentation appearing to be spirally arranged, with bulbous thickenings and numerous free ends.

Spores coppery in mass, individually pallid, pale red to almost colourless in transmitted light, very minutely warted (viewed under oil immersion) with a few groups of larger warts, 6–8 μm diam.

Plasmodium yellow, then white, becoming pink as the sporangia ripen.

Habit. On dead wood, and occasionally other substrata.

Myxomycetes play an important role in the natural environment, especially for the species developing in oil and decaying wood. These organisms act mainly as regulators of bacterial numbers, stimulate the decomposition rate of organic matter and formation of bacterial communities, and participate in the processes of humus formation and wood decay.