from The Century Dictionary and Cyclopedia
- n. A genus of pyrenomycetous fungi having the perithecia embedded in black stromata and the spores two-celled and hyaline or light yellow. About 20 species have been described. P. morbosa is a parasite which attacks plum-and cherry-trees and forms more or less extensive warty excrescences on the branches, called black-knots. See black-knot, 2, and black-knot of the gooseberry.
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