A while back Gala Solari sent me the picture above, asking what it is. Her description:
"Goopy mushroom thingy. Grows on the mulch. Size ranges from 3" to 18" with irregular shapes. In this pic, it's drying out, when new it's smooth on top, with kind of a skin and goopy inside. When dried out, it's dusty and black-ish. Something eats it. What is it?!"The consensus of George Lantz and soon to be Master Naturalist Mark Bower was that it is a slime mold, mostly likely Fuligo septica - better known as dog vomit slime mold or scrambled egg slime. Interesting juxtaposition of names, eh? George had this further comment.
As in Gala's case, it is commonly found on wood mulch after watering or a rain. It is typically 1 to 8 inches in diameter and up to an inch thick."You say that something is eating it? Believe it or not, Fuligo septica is edible. Native people in parts of Mexico gather and scramble similar to eggs. I would not gather and try it myself."
Slime molds aren't fungi although they have some similarities. Unlike most fungi whose spores drop down from the forming structures, F. septica's spores are produced on or in aerial sporangia and are spread by wind. Gardening sites are peppered by questions about how to prevent them from recurring and many people try to hose them off. Guess what? That just spreads their spores all over the mulch. Tom Volk suggests learning to love them or paving over your garden.
F. septica has several interesting talents. For one, it is able to absorb massive amounts of zinc that would be toxic to any other living thing. It does this by producing fuligorubin A, a yellow pigment which chelates metals into an inactive form. This has some potential for detoxifying soil.
Mark Bower is a good source of slime mold stuff. His email prompted a slime mold blog in 2011 and he just did it again with this Scientific American article. This further describes the ability of the mold to negotiate complex mazes. Maybe some day we will have a self propelled soil detoxifier. I have the perfect name... the blob!
Tom Volk has an interesting article on Fuligo septica including the fact that it was the inspiration for the classic 1958 SciFi thriller The Blob staring Steve McQueen. I am waiting for a morel spinoff.