Pycnidia
Small bodies, very like perithecia (see Perithecium) in general appearance and form, only they are usually smaller, paler, and thinner walled; and the spores in them, instead of being inclosed in asci, are situated, singly or in chains, on the tips of small branches of mycelium that arise from the inner surface of the wall of the Pycnidium The spores are called stylospores, because of being produced at the tips of these slender, rod-like branches, like a stylus, or pen. A reference to Pleospora, of which Phoma is a Pycnidial form, will help to render clearer the relation of this form of fruit to the perithecia.