#086: Morchella esculentoides, a Yellow Morel

It’s morel season! Keep an eye out for these beautiful, tasty mushrooms now through late may!  There are a few species of Yellow Morels in North America, but Morchella esculentoides is the most common one.

Morels are easily identified by their unique shape.  It’s rather hard to describe if you’ve never seen a photo of one, so please refer to the image on the link.  I like to describe Yellow Morels as the Salvador Dalí version of a pinecone trophy.  You start with a yellow pinecone sitting on a pedestal and then distort the image so that the organized gaps in the pinecone become irregular pits and the classic pinecone shape becomes more rounded and lumpy.  Others liken the morel shape to a sponge or a mulberry fruit.  None of these descriptions quite do morels justice.

Yellow Morels are so named for their lighter ridges, which can be whitish to light gray to yellow to tan to light brown.  Until recently, morels with gray ridges were thought to be a separate group of morels.  It turns out that the so-called “gray morels” are simply an immature form of Yellow Morels.  The pits have a darker color than the ridges and can be light brown to dark brown to almost black.  Both the ridges and the pits tend to darken with age and may discolor reddish-brown in spots.

M. esculentoides can be separated from other Yellow Morels by its shape, ridges and pits, and lack of bruising. The head of M. esculentoides is roughly egg-shaped with a more or less conical tip. It is usually 2.5 to 11cm tall and 1.5 to 6cm wide, although some specimens may get twice as big.  The morel’s stem is roughly conical to cylindrical with a swollen base and is slightly to distinctly wrinkled.  It is usually 2 to 12cm high and 1.5 to 10cm wide, although specimens left alone in ideal conditions can get much bigger.  Morels tend to be smaller earlier in the growing season (like now) and larger later on.  Another useful feature for identifying M. esculentoides is its randomly oriented ridges and pits.  Other yellow morels organize their ridges and pits into noticeable columns, but those of M. esculentoides show no organization whatsoever.  If you’re still not convinced, you can check for a bruising reaction.  Although older specimens may discolor, M. esculentoides will not bruise when its flesh is damaged.

You can find M. esculentoides all across North America.  East of the Rocky Mountains, it prefers hardwoods but can be found under conifers.  This morel particularly likes White Ash, Green Ash, old apple orchards, and dead/dying American Elm.  West of the Rockies, it is usually found under hardwoods near river bottoms or under planted ash or apple trees.  The role of morels in the ecosystem is not fully understood.  While they clearly have relationships with living trees, they also tend to fruit under dying trees.  This suggests that they may be mycorrhizal at some points in their life and saprobic at others.

Unfortunately, the description above also applies to M. cryptica.  M. cryptica is morphologically identical to M. esculentoides, but has a more limited range.  While M. esculentoides can be found all across North America, M. cryptica is restricted to the Great Lakes and north central Appalachians (from Illinois, west to Virginia, and north to western Pennsylvania and Ontario).  Both species are edible, so the average mushroom hunter probably doesn’t care which species his/her collection represents.  If you are dead-set on properly identifying your collection, you will need to do some DNA analysis (it’s named M. cryptica for a reason).  Perhaps with your diligent work, we’ll be able to find some morphological differences between the two species.

In addition to M. cryptica, there are a number of other look-alikes to M. esculentoides.  Other Yellow Morels can be eliminated by checking them against the description above.  All Yellow Morels are edible, so if you just can’t figure out which species yours is, it’s OK.  There are also a few false morels (FFF#0344) and verpas (FFF#067) that beginners can confuse with Yellow Morels.  These can easily be eliminated by morphological characteristics.  If you cut a morel in half, you will clearly see that the head and stipe are hollow and that the head attaches directly to the stipe.  False morels have a solid stipe and a head that attaches only at the very tip of the stipe.  Verpas have a hollow stipe that is filled with cottony fibers and a head that is attached only at the tip.  False morels should be avoided, as they contain toxins that can cause severe reactions in certain cases.  Verpas tend to be less poisonous, but the effects vary from person to person.

Along with all other morels, M. esculentoides is placed in the phylum Ascomycota, class Pezizomycetes, order Pezizales, and family Morchellaceae.  M. esculentoides is a recent addition to the genus, having been described in 2012.  Before that, it (along with M. cryptica) was classified as M. esculenta, which is now a strictly European species.  “Esculent” means “edible” or “fit to be eaten” and is usually applied to vegetables.  This name certainly befits the Yellow Morels.  If you look at a morel under the microscope, you will find that the asci (spore-producing cells, see FFF#012 for more info) are located in the pits of the head, but not on the ridges.  The pits, therefore, protect the asci from the elements while ensuring that each “spore cannon” has a direct line of sight to the surrounding air.

Finally, what morel post would be complete without discussing edibility?  Morels are edible, but they must be cooked first.  Raw morels often cause gastrointestinal distress, so DON’T be tempted to eat one of your freshly-picked mushrooms!  Cooked morels have a strong flavor and meaty texture, meaning they can stand on their own in dishes.  Unlike truffles, which are used only to add flavor, morels can be the centerpiece of a meal.  Yellow Morels are probably the favorite kind of morel in North America because of their superior flavor.  They can be found in grocery stores, but it is much cheaper to collect your own.  So look for these beauties the next time you visit the forest!

See Further:

http://www.mushroomexpert.com/morchella_esculentoides.html

http://mdc.mo.gov/discover-nature/field-guide/yellow-morel-common-morel-0

http://americanmushrooms.com/morels.htm

http://www.sierrapotomac.org/W_Needham/YellowMorel_050503.htm