Octospora and Inermisia in Western Europe

Abstract

Summary. A key is offered to nineteen species of Humariaceae, three of them new, assigned to the genus Octospora Hedwig ex Gray and to six species transferred to Inermisia Rifai. There is a rather well defined group of small Pezizales, with yellow to orange disks and white receptacles, the members of which grow in association with mosses, and fruit usually during winter or early spring. Some species have recognizable hairs on the receptacle, especially near the margin, others have not, and on this basis they have traditionally been assigned to two genera, usually placed in different tribes if not different families. The hairy species have been referred to Neottiella, or more recently to Leucoscypha, and their taxonomy has not been particularly difficult. For the nominally hairless species a succession of names has been in vogue: Leucoloma, Humaria, Humarina and latterly Octospora which, since it dates from 1821 , is at least reasonably secure from supercession on the ground of priority while the current rules of fungus nomenclature are observed. These fungi have been little studied and the naming of collections often presents considerable difficulty. In recent years one of us (H.I.) has found them rather plentifully at the appropriate season in the central Rhineland and has been able to investigate their association with different genera of mosses, a feature usually neglected by mycologists whose descriptions commonly refer to no more than an association with small mosses in general or to occurrence on mossy ground. Rather inconspicuous as they are, and neglected by modern mycologists who do not collect at the appropriate time of year, these were among the first ascomycetes to be subjected to critical microscopic study, by the pioneer bryologist John Hedwig. He discovered the presence of consistently 8-spored sacs in the hymenium of 'Discomycetes' and accordingly coined for them the generic name Octospora in the second Tome of his monumental 'Descriptio et adumbratio microscopico-analytica Muscorum Frondosorum nec non aliorum vegetantium e classe Cryptogamica Linnaei', dedicated to King George III