Slime Molds

Specimen #15: Physarum viride, N/A

Figure 1: Physarum viride on its original substrate. This specimen was found on a plywood board. What is shown here are the fruiting bodies which have emerged from the board. The remaining parts, especially the plasmodium, of this acellular slime mold are most likely strewn throughout the fibers of the board. However, due to the intense sunlight, this specimen was desiccated. Luckily, it was able to be re-hydrated later.

Figure 2: Physarum viride at a scale of 20 um. This is the sporangium of the specimen after being re-hydrated, with its floriform, or flower-like, peridium intact. This species can have a different variety of sporangium shapes, including being shaped like a typical mushroom or floriform, like shown here. Also, instead of having a spore case directly attached to the substrate, this species forms a tiny, delicate stalk.

Name: Physarum viride

Common Name: N/A

 Family: Physaraceae

Collection Date: October 15, 2016

Habitat: On dead wood or the bark of living trees.

Location: On a plywood snake board in a goldenrod dominated meadow in James H. Barrow Field Station, OH.

Description: Plasmodium yellow or greenish yellow. Sporocarps stalked, gregarious, up to 1.5 mm tall. Stalk subulate, varying from pale yellow or reddish and darker below to nearly black, usually relatively long. Sporotheca nodding, lenticular or subglobose, umbilicate below, yellow to orange, 0.3-0.6 mm diam. Peridium delicate, encrusted with calcareous flakes, splitting into irregular fragments above and floriform lobes below. Capillitium dense, the nodes mainly fusiform, orange or yellow, connected by hyaline thrends. Spore-mass fuscous or violaceous black. Spores bright violet, nearly smooth, 7-9 µm in diameter.

Key Used: Discover Life. 2016. http://www.discoverlife.org/20/q?guide=Mycetozoa_GSMNP

Keying Steps:

Identified using visual description. This specimen is a bright yellow in color and has stalked sporocarps.

Slime Mold Links:

http://www.discoverlife.org/mp/20q?search=Physarum+viride