Abstract
The anatomy, morphology and gross histochemistry of the germinating embryo and seedling of Paulownia tomentosa (Scrophulariaceae) is described. Cytohistological changes in the shoot apex are correlated with anatomical and histochemical differences. During the first days of germination and before leaf primordia are formed, there is a gradual increase in staining for cytoplasmic protein and RNA. Once the first leaves are initiated, the staining for these compounds remains constant in the central mother‐cell zone, and further increase in protein and RNA is confined to the developing leaf primordia. Starch grains are found in all areas of the very young apex, but with anatomical maturity the grains are restricted to the central mother‐cell zone. Some electron micrographs point up special cytological features.