aecium

• æcium

From New Latin, from Ancient Greek αἰκία (aikía, “injury, insult”). However Merriam-Webster relates that aecium is a back-formation from aecidium and is not related to the Greek aikía. The word aecium was "introduced as a substitute for aecidium by the Purdue University plant pathologist J. C. Arthur (1850-1942) in an effort to reform terminology for rust fungi; see Terminology of the Spore-Structures in the Uredinales, Botanical Gazette, vol. 39 (Mar., 1905), pp. 219-22." [1]

• IPA^(key): /ˈis.i.ʌm/

aecium (plural aecia or aeciums)

1. (mycology) A cuplike fruiting structure of some parasitic rust fungi that contains chains of aeciospores.
   • 1932 August, Ralph Ulysses Cotter, Factors Affecting the Development of the Aecial Stage of Puccinia Graminis, US Dept of Agriculture, Technical Bulletin No. 314, page 29,

     The writer therefore made observations to determine the conditions under which the aecia open and discharge spores most readily.

   • 2010, N. K. Soni, Vandana Soni, Fundamentals of Botany, Volume 1, page 127,

     The receptive hyphae with binucleate cells eventually form the basal cells of the aecium. […] Many cup-like structures, called aecia, appear on the lower surface of leaf.

   • 2010, M. S. Patil, Anjali Patil, 16: The Rust Fungi: Systematics, Diseases and Their Management, Arun Arya, Analía Edith Perelló (editors), Management of Fungal Plant Pathogens, page 209,

     It is a heteroecious rust and its aecia are produced on species of Oxalis, namely O. stricta, according to Arthur (1929).

• aecial
• aecidium

• pycnium

• aecium at OneLook Dictionary Search
• aecium in The Century Dictionary, The Century Co., New York, 1911