A canker disease of the Cupressaceae in Kansas and Texas caused by Seiridium unicorne.

Seiridium unicorne caused cankers on Oriental arborvitae (Thuja orientalis) and eastern red cedar (Juniperus virginiana) in Kansas and Texas and on Italian cypress (Cupressus sempervirens), Arizona cypress (C. arizonica), and Leyland cypress (Cupressocyparis leylandii) in Texas. The fungus also was associated with small, annual cankers on bald-cypress (Taxodium distichum) in Kansas landscape plantings. Cankers on Rocky Mountain (J. scopulorum) and Chinese (J. chinensis) junipers and on northern white-cedar (T. occidentalis) developed 1 mo after inoculation in greenhouse or field studies. No evidence of host specificity in fungal isolates was found