Technical Abstract: Phoma species invade wheat in India, Mexico, Australia and parts of South America, and have been reported as secondary invaders in the United States and Germany. The pathogens are widely distributed on numerous hosts but relatively rare on wheat. Most of the Phoma species reported on wheat are opportunistic parasites: P. glomerata (Corda) Wollenw. & Hochapfel is associated with leaf spots and blights, P. subglomerata Boerema, Gruyter & Noordel. acts as an opportunistic parasite causing leaf spots during wet periods, P. macrostoma var. macrostoma Mont., a wound parasite found on weakened hosts, causes leaf spots, and P. americana Morgan-Jones & J.F. White is associated with nematode cysts. Phoma sorghina (Sacc.) Boerema, Dorenb. & Kesteren (reported under the synonymous names P. insidiosa Tassi and P. indianensis [K.B. Deshp. & Mantri] Boerema, Dorenb. & Kesteren) is a seed-borne pathogen causing minor leaf spots. In inoculation experiments, P. triticina E. Müll. was reported to cause moderate damage, but it is unclear how damaging it is under natural conditions. Phoma lophiostomoides Sacc. occurs on leaves and culms of wheat in Australia and Europe, but its disease characteristics have not been reported. Phoma subglomerata, P. sorghina, P. triticina, and P. americana, are restricted to Poaceae (grasses), while the other Phoma spp. infecting wheat are plurivorous, occurring on a wide range of hosts from multiple plant families. P. sorghina invades wheat glumes and awns in India, causing oval, brown lesions, with pycnidia in their centers. Wheat and triticale in Mexico occasionally show dark brown lesions on leaf sheaths caused by P. glomerata. Prolonged periods of continuous wetting are required for infection and symptom development. Controls are not prescribed, but cultivars ranging from highly resistant to highly susceptible have been identified in greenhouse tests.