Hypothallus

In true slime molds (myxogastria), lichens, and in species of the family Clavicipitaceae, the hypothallus is the layer on which the fruit body sits, lying in contact with the substrate.

The word is derived from the Ancient Greek root hypó ("under") and thallós ("shoot" or "thallus").

In the "epihypothallic" Stemonitida, the hypothallus forms hollow, tubular stems and a columella,[3] up which the remaining plasmodium then rises, producing the spores.

Here, the hypothallus produces a layer on the plasmodium, which creates the rooms of the single fruit bodies during fructification.

Here, the hypothallus is part of a morphological unit with peridium and stem, which serves as a membranous surface of the whole structure with the spores.