Kochia scoparia as a factor in inhalant allergy

Abstract

1. 1. During recent decades, particularly the last, Kochia scoparia (Mexican fireweed, burning bush, summer cypress), a pernicious introduced weed of the goosefoot family, has spread rapidly in eastern Colorado, western Kansas, the Dakotas and western Iowa. 2. 2. It has now become established in urban centers as far east as Detroit and as far south as St. Louis. Atmospheric concentration of the pollen of Kochia scoparia has now reached significant levels as far east as central Iowa. 3. 3. The plant is a successful rival of Russian thistle and is already replacing ragweed locally. 4. 4. The present hazard is that of a new, active inhalant pollen in the middle Mississippi Valley where ragweed has heretofore been dominant.