General Notes.
The Ascomycetes differ from all the other fungi so far dealt with in that the spores develop enclosed in a microscopic envelope or sac—called the ascus. Usually eight spores are produced in each ascus and they are often dispersed violently into the air. Elf-cups and morels are typical Ascomycetes, but the group also includes innumerable minute forms of the microscopic fungi, small discs, minute flask-like structures, some of which are parasitic on leaves and stems of higher plants. In number the large species of Ascomycetes are few when compared with the others and therefore can only be given but a mention in the present account. When collected the Ascomycetes can be distinguished from the Basidiomycetes by simply examining a slice of the spore-producing tissue where the tell-tale asci will be seen (see [p. 21]). If the fruit-body is placed in a tin when collected and opened in a warm room all the mature asci explode at once producing a cloud of spores visible in the air immediately over the fruit-body.
Aleuria aurantia (Fries) Fuckel Orange-peel fungus or Scarlet elf-cup
Fruit-body: diameter 25-50 mm.
Description:
Fruit-body: cup-shaped then undulating and becoming flattened, irregular, sometimes split and lacking a stem.
Inner surface: bright orange.
Outer surface: whitish and minutely downy.
Flesh: thin and white.
Spores: very long, ellipsoid, ornamented with a coarse network which projects at each end, and 17-24 × 9-11 µm in size; eight contained in an elongate, cylindric ascus.