The moisture content of the product when it is in equilibrium with the surrounding atmosphere is called the equal moisture content or hygroscopic equilibrium. Epigeal Plants in which the cotyledons appear above the surface of soil. Epicotyl The growing point of the embryo, which gives rise to the shoot, or the above ground part of the plant. Ergot 1. A disease of grasses and Cereals caused by the fungus Claviceps purpurea. 2. The Sclerotium of this fungus, which replaces the seeds of the host, and contains alkaloids which cause ergotism in animals and man.