By Staff
Every morel mushroom hunter east of the Great Plains knows you never pass by a dead elm tree or snag without giving the nearby area a thorough inspection.
We all know there is some sort of relationship between morels – the yellow and white versions, not the gray's and blacks – and dead elms. I, and surely you, too, have long wondered just what this secret, magical relationship is. Years of casual searching for a scientific answer turned up nothing. In fact, some professional botanists I talked to denied there was any relationship at all, it was just coincidence. C'mon, get your heads out of the dirt. I'd venture a guess that at least 80 percent of the yellow/white morels harvested come from the base of dead and dying elms. Most mushroom aficianados are also convinced yellow/white morels have a similar relationship with old apple trees and, to a lesser degree, sycamore trees. When it comes to the earlier sprouting black morels, their relationship seems to be with cherry and poplar trees, though not so definitive as the white morels and the elms. Many also believe gray morels hang out around ash trees.
I've finally found a web site, morel-farms.com, with what seems a plausible answer to the relationship between morels and elms. A few years ago a gent by the name of Stewart Miller from Lafayette, Ind. dove into this and got to the root of it, pun intended as you're about to see. First you must know how mushrooms grow. The main body of the mushroom plant is the mycelium which, in the case of morels and many other fungi, grows to a large size underground. When the time of year, soil moisture and temperature becomes right the mycelium produces a fruit, if you will, that pops above ground. This is the mushroom we harvest.
According to Mr. Miller, in the case of morels the mycelium first invades the roots of healthy elm trees (and certain other plants). Miller actually has pictures of this invasion. It does no harm to the tree. In fact, it helps the tree by decomposing organic stuff in the soil and converting cellulose and starch into simple fructose and glucose, fancy terms for sugar, which the elm's roots readily absorb.
He reports a morel infected tree actually grows faster and healthier than a non-infected one. In turn, the morel gets to hang out in the roots tapping some of the sap for its sustenance. As long as the elm tree remains healthy the morel isn't inclined to leave its happy home and just remains status quo underground. That's why we don't find morels under live elms. But then, inevitably, along comes Dutch elm disease and the tree dies.
With the sap source gone, the morel mycelium withdraws from the roots and with sufficient moisture and warmth the mycelium is stimulated to produce fruit and the morel mushroom pops up through the ground. To capitalize on this process Stewart Miller sells morel infected elm tree saplings for planting (see above mentioned website). Obviously not a quick trip from planting to skillet but with patience…. who knows?
If this is the answer to the mystical morel/tree relationship it leaves us hanging as to the aforementioned association of morels with other live, healthy trees such as apple, sycamore, cherry, poplar and ash. Must these trees be somehow stressed to reduce sap flow and stimulate the morel to fruit? Or perhaps these other trees don't hold as much water and sap as an elm (live elms do hold a tremendous amount of water – I've seen fresh cut elm stumps gush water like a drinking fountain for hours) so the morels don't take up such complete residence and are more apt to fruit without cause. Or maybe there is no true relationship with morels and these other trees, they just have identical soil and growing condition preference and so are found together. We're obviously back to speculation there. That's just as well for the mystique surrounding morels greatly enhances the quest. Carpe diem.