PRESENCE OF PYCNIDIA IN FRUIT-BEARING AND STERILE FORMS OF USNEA-FLORIDA (L) HOFFM (LECANORALES, USNEACEAE)

While proposing a distributional study of the genus Usnea in the midla nd area Spessart, Germany (Hessen and Bavaria), all thalli of a popula tion of Usnea florida were investigated if or if not pycnidia and/or a pothecia were present. Localization of pycnidia on the thallus, as wel l as their anatomy and placement within the thallus are described. Som e considerations about the controversial opinions of the function of t he pycnospores are given. In addition, the relation of Usnea florida, as the fertile, apothecia bearing partner and Usnea subfloridana, as t he sterile, soredia bearing partner of a ''species pair'' is discussed .