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Half free morels, Morchella punctipes, feature a stem that is attached halfway up the
cap.  Other morels have stems that are attached closer to the bottom of the cap.  
Can be found in abundance in some years, which is good because they are rather
leggy (more stem than cap).  Although, some people love the fried stems as much as
the caps.
It has been determined that there are as many as 19 different species of morel mushrooms
in North America.  
Taxonomic revision of true morels (Morchella) in Canada and the United
States, 2012, Michael Kuo, et al. It is hard to tell many of these mushrooms apart by looking
at them, but there are several groups that have defining characteristics.  In the Midwest,
three familiar groups are the black and two yellow morels.  Another morel, the half-free
morel, is separated from these groups by its stem/cap attachment. All of these mushrooms
are choice edibles.  Found in spring, early April to late May, give or take a week or two.  
Prime time in southern Indiana is mid April to mid May.
In the Midwest, the black morel, Morchella angusticeps, is the first to appear in early April with the
spring rains and warm nights.  Seems to have an association with ash and poplar trees, but is
also said to be found under a variety of other trees, including conifers.  
The classic yellow morel, Morchella esculentoides, usually fruits in late April and into mid May.  
Large finds are often associated with ash trees, dying elm trees and old apple orchards; can
also be found growing under other hardwoods and conifers.  These golden yellow examples
have light colored ridges and pits.  Warm nights and rain during the season brings on more
mushrooms; cold nights and dry conditions equals fewer mushrooms.
The poor gray morel has turned out to be a yellow morel in disguise, so says the DNA; but it
still gray (and mighty tasty, I might add).  Studies have shown that the gray morel, with its
dark pits and light ridges, is genetically identical to the classic yellow morel,
.  The color variation may represent immature specimens or may be caused by
factors such as climate, substrate and/or tree association.  Who knows?  Nobody.
Morchella diminutiva, this creamy yellow to golden yellow morel is
distinguished from the yellow morel by its smaller size and pits that are
more defined and usually vertically arranged.  This morel can be found
throughout the morel season.  
Where can it be found?  In the woods.
Morel Mushrooms