
Wasp's Nest Slime Mold (Metatrichia vesparium)
These stalked fruiting bodies were found growing in clusters. Several empty sporangia (goblet-shaped, spore containing structures) were present, but there were partially intact (and remnants of) apical caps in places as well. There were also several orange masses of capillitium, fluffy structures that aid in spore dispersal, ultimately springing open the sporangia through their coiled force.
Growing on Water Birch (Betula occidentalis) at a forest edge.

Fruiting body a stalked (or rarely sessile) sporangium, gregarious to clustered, 1.0–1.5 mm tall. Sporotheca obovate, usually firmly united into clusters, erect, wine-red to dark maroon or sometimes nearly black, individual units 0.4–0.7 mm in diameter. Hypothallus membranous, contiguous for a group of sporangia, colourless to dark red. Peridium opaque, firm, shining, often with metallic reflections, dehiscence by a preformed dome-shaped operculum. Stalk solid, rather thick when supporting several.. more
