Missouri Master Naturalists- Springfield Plateau Chapter

Thursday, April 30, 2020

Slime or Flux

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

On a hike on a friend's path we came across these beautiful orange and yellow blobs, standing out in shaded woods.  Maybe beautiful is an overstatement, gnarly would be closer,  but they did catch my eye.  They were on the ends of 5" diameter grapevines that had been cut months before.  On closer inspection we could see clear liquid dripping off the surface as you can see here.
 
Mark Bower identified this for me as stump flux, aka deer vomit, neither of which are compliments.  He also shared one of his photographs with me.  If you are a regular visitor to the blog you have seen his beautiful fungus and slime mold photographs, but this isn't one of them.

Slime on a branch - Mark Bower






In the spring, tree roots send up sap toward its branches, delivering the fuel to grow new shoots and leaves.  Trees wounded from bark damage, deer rubs, or the subtle effects of a chainsaw may continue this and the sap will still exude from the wounds.  This is the same process that produces real maple syrup.

Slime fit for a fly
The sugary sap forms a watery translucent slime.  Yeasts are drifting around in the air and once they attach they grow by digesting the sap.   Yeast + sugar = fermentation.  Add some bacteria and fungi and you have a feast for insects like flies, ants, and maggots.  All the ants and flying insects covering this stump scurried away before I could get their pictures, leaving this lone fly.

The slime is translucent and greasy but the filamentous fungal growth was quite hard to the touch.  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 fact with young children who are eating their vegetables.)

Stump Dog* - Cornell
*Stump Dog in his matching coat "nose" his slimes and shares his more scientific details referred to above at his blog at mycology.cornell.edu.