Elasmomyces, Arcangeliella, and Macowanites

Abstract

Elasmomyces and Arcangeltella were erected by Cavara to receive those forms related to Hydnangium but having a columella. In Elasmomyces the gleba may pull away from the base of the substipitate columella at maturity, while in Arcangeliella the gleba remains attached to the columella although the peridium may break away from the base partially exposing the lower part of the gleba. Arcangeliella also has lactiferous ducts in the trama, the peridium, and the columella. These characters seem important from the standpoint of comparative morphology and are worthy of generic distinction.-The lactiferous ducts at times are scant and may require careful staining. The study of the columella in fresh material is rather simple, but in dry herbarium specimens it may not show more than as a line. If whole or large sections of specimens are present they may be made to regain almost natural stature by soaking, rendering even a slight columella apparent and readily studied. When the fructifications have been sliced thin, as in many of the older collections, this character may be ambiguous. Macowanites is similar to the above two genera in some respects, but for the most part the species are larger and are more pileate than in Elasmomyces. One species with lactifer-