365 Urban Species. #158: Wolf's Milk

[urbpan]

Location: Perimeter of Brookline water and sewer division landscaping wood chips.

Urban species #158: Wolf's milk Lycogala epidendrum

A slime mold is a strange organism, stranger even than its name implies. It behaves like an animal, but reproduces like a fungus. It spends much of its life as a mass of protoplasm (properly called a plasmodium), which contains millions of nuclei unbounded by separate cell membranes. This mass slowly moves about on decaying wood, consuming organic particles. At some point when the time is right (or when conditions become dry or the food is depleted), the plasmodium coalesces into a more or less solid fruiting body, and releases spores. The fruiting body stage is the form that is usually encountered (as is the case with true fungi).

In the case of wolf's milk, the fruiting bodies appear as a collection of orangish-pink spheroids. If damaged in this stage, the liquid spore mass oozes out. In time the globules turn purplish, then brown. The spore mass dries out, and the spores disperse.

Slime molds can be alarming in the way that they seem to appear from nowhere, and their name doesn't help. The alternate name "myxomycete" isn't much better, and I've never been able to get away with a short explanation of what these creatures really are. What people need to know is that they are not harmful in any way, and they aren't indicators of anything except wet wood. They crawl around on the wood chips while we are sleeping, and the next day they are pretty little beads of pink goo. Just another urban species that goes on with its business whether we care to notice them, or not.



A damaged wolf's milk globule next to a dusky slug--wet wood chips are favorable conditions for both organisms.


Somewhat more mature wolf's milk fruiting bodies. (this and next photo by cottonmanifesto)


Spores from mature fruiting body.


Fully mature wolf's milk fruiting bodies. (Location: Drumlin Farm)