Abstract
The outgrowth of female involucres into vegetative thallus structures in the genus Metzgeria is 1) taxonomically more correlated with the primitive groups and is commonly produced in those 16 species, without sporadic occurrence in other species (it occurs rather uncommonly in northwestern European M. furcata, 2) geographically confined largely to the tropical Andes, 3) apparently correlated, in most cases, to the development of archegonia, calyptra and sporophyte. Such outgrowth was recorded by Stephani earlier in his Species Hepaticarum Vol. 1: very brief descriptons of female involucres of M. acuminata, M. adscendens Steph. (Guiana, Brazil), M. filicina and M. imberbis indicate clearly or at least suggest such structures. In both volumes 1 and 6 there are a few other species with similar descriptions; these apparently refer to only somewhat longer (larger) involucres. The presence of a fine illustration of an outgrown female involucre, associated with a calyptra, was noted in his unpublished Icones, of M. adscendens.
