Slime Molds ?

February 27, 2014Today’s weather is almost a repeat from three days ago, and again I stay out in it for most of the day. I’m back at the Weston Lake Boot area to resume my tree measuring. The largest sweetgum I find today is 15.2 feet in girth and 120 feet high (the uppermost canopy limbs appear to be replacements). I also measure a green ash that comes in at 13.3 x 117 feet. A fourteen-foot circumference ash is considered big for this species, and I don’t think I have ever measured one greater than fifteen feet.

February at Congaree brings to mind any number of seasonal events and sightings – ripening red maple seeds, courting (and noisy) red-shouldered hawks, the sonorous calls of leopard frogs, fish crows returning from their coastal winter quarters, and slime molds. Slime molds you say? You know, those bright orange globs of protoplasm that stand out like orange flagging in otherwise somber winter woods. Today I see my first one for this year about 150 feet through the trees. It’s only about two inches in length and as usual, oozing from sapsucker holes in a grape vine. February is slime mold month at Congaree, but this has been such a cold winter that they are getting a late start. I check on this mold colony twenty-five days later and find only a few, clear fresh drippings (they make a rather brief appearance and disappear by early spring).

Slime molds are neither plant nor animal. They used to be considered fungi but are now placed in their own kingdom, the Protista. They form large blobs of multi-cellular organisms called plasmodiums and feed on decayed organic matter. It has recently come to my attention, however, that my orange blob may not actually be a true slime mold but rather a tree slime fungus known as Fusicolla merismoides. Unlike slime molds that feed on bacteria and other micro-organisms associated with decaying organic material, the orange blob is nearly always found on live grape vines (I’ve never found one anywhere else) where it apparently lives off of the sugary sap that starts flowing in late winter, typically from drilled holes created by yellow-bellied sapsuckers. It is also speculated by some mycologists (those that study fungi and mushrooms) that the orange blob may actually consist of several different species of fungi.

The orange blob has an extraterrestrial appearance at close range (they also move, albeit slowly, as well as grow) and remind me Hollywood horror flicks from the 1950s. Whatever it is, I will probably still continue calling the orange blobs slime molds and look forward each February to seeing their bright orange coloration brightening up Congaree’s winter woods.