aecidium

• æcidium

From New Latin aecidium, the diminutive form of Ancient Greek αἰκίᾱ (aikíā, “injury”).[1] However Merriam-Webster takes the origin from Ancient Greek οἰκίδιον (oikídion) and refers to the botanist John Hill, in his A General Natural History, or New and Accurate Descriptions of the Animals, Vegetables, and Minerals, of the Different Parts of the World, vol. II, A History of Plants (London: Printed for Thomas Osborne, 1751), p. 64: "We have called this genus, distinguished by its peculiar cells, Æcidium, from the Greek οικιδιον, cellula."[2]

• (Received Pronunciation) IPA^(key): /iːˈsɪdɪəm/

aecidium (plural aecidia or aecidiums)

1. The cupulate fruiting body borne upon the mycelium of certain fungi commonly parasitic upon specimens of the Compositae, Lamiaceae, Leguminosae, and Ranunculaceae families
2. (mycology) A member of the form genus Aecidium.

• teliospore
• urediniospore