Chocolate Tube Slime

The Chocolate Tube Slime Mold (Stemonitis splendens) is a species of myxomycete (plasmodial slime mold) in the family Stemonitidaceae, found worldwide in temperate and tropical regions wherever there is decaying wood, leaf litter, and moist conditions. Stemonitis species are characterised by their elegant, upright, tube-shaped sporangia arranged in dense clusters — the sporangia of S. splendens are typically 10–20 millimetres tall, chocolate-brown to rust-brown in colour, and supported on individual stalks (stipes) arising from a common base. The spore mass within each tube is supported by a fine internal network of threads called the capillitium. Despite resembling plants or fungi, slime molds are protists — during their vegetative phase they exist as a large, multinucleate, mobile plasmodium that engulfs bacteria and fungal spores as it moves through decaying organic material. The plasmodium aggregates and differentiates into fruiting bodies when conditions become unfavourable, releasing millions of wind-dispersed spores. Chocolate Tube Slime Mold is not evaluated by the IUCN; as a cosmopolitan protist, it does not meet criteria for conservation listings. It is a common and iconic subject for amateur naturalists and is frequently photographed on decomposing logs in temperate woodland. Its ecological role in decomposing wood and recycling nutrients is significant.