The possible allergenicity of an insect pollinated weed,Echium plantagineum, was investigated in a rural area of Australia. Sixty‐one subjects with respiratory allergy were studied. Positive skin test reactions to defatted ammonium bicarbonate extract of pollen were found in over 60% of subjects, and positive RAST tests in a similar number. The question of cross‐reactivity between weed pollens is discussed. The pollen ofE. plantagineumwas shown to reach the atmosphere in significant amounts about 1 month before the peak grass pollinating period. Evidence that the pollen ofE. plantagineumbecomes airborne and elicits an IgE response suggests that further attention should be directed to weed pollens as potential allerg