A scanning electron microscope study of the internal structure of mature linear mycelial organs of four basidiomycete species

Abstract

The internal structure of mature mycelial cords of Lycoperdon pyriforme, Mutinus caninus, Steccherinum fimbriatum, and Tricholomopsis platyphylla was studied using scanning electron microscopy. Although interspecific differences in the degree of internal differentiation were observed, linear mycelial organ structure in all four species was similar, in that they consisted of a cortex of fine hyphae surrounding a medulla containing large diameter "vessel" hyphae. Based on similarities between the internal structure of rhizomorphs of Armillaria mellea and the mycelial cords of the species considered in this study, the exclusive use of the term "rhizomorph," qualified by adjectives describing development at the growing front and the degree of internal differentiation, is proposed in describing all linear mycelial aggregates.