A revised Mycosphaerella gregaria nom nov for M-aggregata on Eucalyptus

As a later homonym of Mycosphaerella aggregata (Schweinitz) Stevenson the name Mycosphaerelia aggregata Carnegie & Keane is illegitimate. The name Mycosphaerella gregaria is proposed as a replacement with similar etymology. The original description is revised following further collections and includes new hosts and cultural characteristics. Originally thought to be a saprophyte, this species may be a primary pathogen of leaves of Eucalyptus.