Sunday, April 30, 2017

Slime or Flux

In the spring a cut stump's fancy lightly turns to thoughts of sap.  - with apologies to Tennyson

If you are a regular visitor to the blog you have seen the beautiful fungus and slime mold photographs of Mark Bower MN.  These are not them.  He sent me these pictures from a recent hike.  Its common names include tree slime, stump flux and slime flux.....well you get the picture.

In the spring, tree roots send up sap toward its branches, kicking in the fuel to grow new shoots and leaves.  Wounded trees from bark damage, deer rubs or the subtle effects of a chainsaw do not always change this and the sap will still exude from the wounds.  This is the same process that produces your maple syrup.

Tree slime on dogwood - MB
Yeasts are drifting around in the air and some love to "digest" tree sap.  Soon they are creating a "watery slime (that) is translucent and greasy with yeast and bacterial and filamentous fungal growth."  The orange to red colors you see are due to carotene produced by the slime, the same chemicals that give carrots their orange color.  (Do not share this paragraph with young children eating vegetables.)

Stump Dog* - Cornell
*Stump Dog in his matching coat "nose" his slime and shares his more scientific details quoted above at the blog at

Photographs by Mark Bower