Boron deficiency is identified as one of the more important causes of poor stem form and malformed leaves in plantations ofEucalyptusglobulusin Yunnan Province, and ofEucalyptusgrandis,Eucalyptustereticornis, andEucalyptusurophyllain Guandong Province. Symptoms of B deficiency inE.globuluswere rolled and malformed leaves, stem dieback, and a prostrate form. InE.urophylla, leaf margins became chlorotic then necrotic, leaves turned brittle and corky, shoots died back, and the upper stem nodes were enlarged supporting numerous short-lived axillary shoots. InE.grandis, stem dieback was preceded by the basipetal accumulation of anthocyanin in leaves. Boron-deficientE.tereticornisleaves developed marginal and interveinal chlorosis and recurved margins. Depressed foliar B concentrations were associated with visible symptoms. InE.globulus, the mean B concentration in young leaves of healthy trees was 31 mg/kg dry matter compared with 10 mg/kg in prostrate trees. Symptoms did not appear inE. globulustrees supplied with B fertilizer at planting. Normal shoot growth was restored inE.urophyllaby the addition of B to the soil.