The featured mushroom for April 2011 was...
a.k.a. the Smooth Thimble Cap or the Bell Morel.
Verpa conica is one of the first mushrooms to fruit in the spring. Though these harbingers of the morel season are small and fragile mushrooms, they are edible. Although the similar species in the genus Verpa, V. bohemica, has caused intoxication-like symptoms, this mushroom has not been known to cause any problems. Occasionally you can find this mushroom in sufficient quantities to warrant tasting though usually only a few are encountered.
The cap of the V. conica is brownish, usually smooth and thimble-like. The cap ranges from 3/8 to ¾ inches wide and from 3/8 to 1 ¼ inches high. The cylindrical stalk is off-white 1 ½ to 2 ¼ high and ¼ to 5/8 inches thick. The stalk is hollow but is filled with cotton-like pith, which can stick to the stalk when it dries with age yielding the appearance of a hollow stalk. The stalk is attached only at the very top of the cap, a feature which distinguishes the Verpas from the half free morel whose stalk is attached half way up the cap. V. conica occasionally has a lobed and wrinkled cap looking like a small Gyromitra, the false morel. The form with wrinkles does not have the vertical ridges of the wrinkled thimble cap, V. bohemica.
Though these small, fragile mushrooms are edible, they are not often found in sufficient quantities to warrant cooking them. When you do find a sufficient quantity to cook, they are not among the choice edibles that grow in the spring. They are worth trying, however.