ENDOGENOUS RHYTHMIC GROWTH OF THE LEAF OF GUAREA-GUIDONIA (MELIACEAE)- PRELIMINARY EXPERIMENTAL-STUDY

The composed pennate adult leaf of Guarea guidonia (Meliaceae) has a m ultiannual rythmic growth shown by the successive sequential setting o f leaflet pairs. This is demonstrated at the level of the foliar centr al vein by the differentiation of periodic rings in the wood. Microsur gically isolated foliar primordia produced large leaves, the tops of w hich supported several foliar sequences. Early removal of foliar primo rdia suppressed the endogenous rythmic growth pattern and the function ing of the foliar apex became continuous. Isolated cuttings of the com posed leaf were readily rooted, the rythmic growth being maintained. T his was also possible with cuttings of isolated nodes. Data show that rooted cuttings of this plant could be used as a model for the study o f endogenous rythmic growth of woody plants.