American plant pathologist (1915–1985).
Abbreviations: M.J.O'Brien
Occupations: phytopathologist, botanist
Citizenships: United States
Languages: English
Dates: 1915-04-10T00:00:00Z – 1985-08-03T00:00:00Z
Birth place: Brooklyn
Direct attributions: 0 plants, 3 fungi
Authorship mentions: 0 plants, 4 fungi