STUDIES ON MANGANESE‐ACCUMULATING ALYXIA SPECIES FROM NEW CALEDONIA

Summary Thirty‐one species of Alyxia from New Caledonia were analysed for their manganese content. Most of the species showed excessive uptake of manganese with a maximum of 1.15% Mn in dried leaves of A. rubricaulis. The manganese content alone was sufficient to distinguish a number of species from each other. Composite samples were in addition analysed for calcium, magnesium, potassium and sodium. Correlation analysis and calculation of the slopes of regression lines showed that manganese uptake was mainly at the expense of calcium, rather than magnesium. Similarly magnesium was preferred to potassium and potassium to sodium. It is possible that manganese may have some physiological role in Alyxia, compensating to some extent for reduced uptake of the nutrients calcium and potassium.