Disciotis venosa, commonly known as the bleach cup, veiny cup fungus, or the cup morel is a species of fungus in the family Morchellaceae. Fruiting from April, they are often difficult to locate because of their undistinguished brown color.
Found in North America and Europe, D. venosa appears to favor banks and slopes and sheltered sites. Although edible mushroom, it may be difficult to identify without microscopy.
Taxonomy
The fungus was first described as
Peziza venosa by Christian Hendrik Persoon in 1801, from collections made near
Klagenfurt, Austria.
Jean Louis Émile Boudier transferred it to
Disciotis in 1893.
Bruno Perco described the form Disciotis venosa f. radicans from collections made in Italy.
The botanical name venosa, meaning "veined", refers to the veins on the inner cup surface. for the species include bleach cup,
Description
Ascocarp produced by this fungus are cup- or disc-shaped, up to wide. The interior surface of the cup, the
hymenium, is dark brown. It tends to become folded into vein-like markings with age, hence the specific epithet
venosa.
The exterior surface is a whitish color, covered with pustules.
There is a short stipe that anchors the cup to the ground.
Although young fruiting bodies are cup-shaped, when they are in diameter, the apothecia split and flatten down to lie in the soil. They are very brittle. The fruit bodies have been estimated to have a lifespan of up to 12 weeks.
The flesh of the fungus has a bleach-like odor when it is broken.
Microscopic characteristics
The
ascospore are elliptical and smooth, with dimensions of 21–24 by 12–14 μm. The
ascus (spore-bearing cells), are 370–400 by 18–20 μm, while the
paraphyses are stout and club-shaped, with tips up to 12 μm wide.
Similar species
Species that may resemble
D. venosa most notably include several species of genus
Peziza, belonging to the family of true cup fungi (unlike
D. venosa which is actually a
morel). Some poisonous ones are also included.
Peziza species generally lack an odor,
have thinner flesh than
D. venosa, and will turn a dark blue color if a drop of
iodine solution is placed on it.
Additionally, the tips of asci in
Peziza species will stain blue with iodine, a feature that can be observed with a light microscope.
Another lookalike, the closely related "thick cup" or "pig's ears" Discina ancilis (also known as Discina perlata or Gyromitra perlata), is edible (or at least not poisonous), has an inner cup surface that is comparatively reddish-brown,
Distribution and habitat
D. venosa is found in North America
(between April and June, especially from the Lower Midwest to New York)
and Europe (including
Bulgaria,
,
,
and
Wales).
It also occurs in Turkey, where it is considered critically endangered.
The fungus is typically found growing on the ground among mossy or needle-covered soil around ; they are often difficult to notice because their brown color typically blends into the background. They have been noted to prefer to grow on banks or slopes rather than flat areas.
Uses
D. venosa is a choice
edible mushroom,
although one author notes that only collectors who have the equipment to check its microscopic properties should consider consuming the species, as it may be confused with several other brown cup fungi.
It may be poisonous unless cooked.
