Summary:
Features include longitudinal, slightly depressed cankers on hazelnut (filbert) trees. In the mature state the cankers contain numerous hard, dark brown to black stromata (also known as pustules), each about 0.2-1cm long, and each with numerous ostioles. Ascospores infect young vegetative tissue in spring (during bud break and early shoot extension) and the fungus colonizes cambial tissue. Stromata containing perithecia develop within the cankers 12-16 months after infection. Stromata form at the margins of cankers each year, so that the cankers expand every year. In Corylus avellana, these cankers eventually girdle branches, causing death of mature trees in 5-15 years. This is known as eastern filbert blight, a destructive disease of Corylus avellana (European hazelnut) which is cultivated commercially in the Pacific Northwest and other areas. Corylus americana (American hazelnut) is affected only in minor ways. (EPPO(1)). Celeste Paley (pers. comm.) has reported it on Corylus cornutus var. californica in BC.

Microscopic:
spores unequally two celled, colorless, the smaller cell remaining as a hemispheric cap measuring 1.1-1.4 x 1.1 microns, and the larger enlarging slowly from July to November from 5-6 x 2-2.5 microns to 8-12 x 4-5 microns at maturity; spore release is typically from November to April; asci are 8-spored - mature asci are 45-65 x 10-15 microns with a long thread-like stalk, within the asci, spores are uniseriate to biseriate; paraphyses are not present in some perithecia and occur in low number in others - they are 40-50 microns long and 3.5 microns at greatest width, and they are short-lived and gelatinize before full development of the ascocarp; the mature perithecium is 1040-2160 microns x 250-830 microns, (Gottwald(1) who provide considerable further microscopic detail in their study of infections in C. avellanea)

Notes:
Anisogramma anomala is found at least in BC, NS, WA, OR, CT, DE, IL, IA, ME, MD, MA, NJ, NY, NC, WI. It occurs naturally on wild Corylus spp. in the eastern United States - it spread to WA in 1973, OR in 1986, and from these states to BC. (EPPO(1))

Synonyms and Alternate Names:
Apioporthe anomala (Peck) Hoehn.