isidium

[ahy-sid-ee-uh m]

noun, plural i·sid·i·a

[ahy-sid-ee-uh] /aɪˈsɪd i ə/. Botany.

a coralloid outgrowth from the thallus in certain lichens.

Origin of isidium

1865–70; < New Latin, derivative of Isid- (stem of Isis) Isis (from the hornlike appearance of the growth); see -ium

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018