Fig. 4

Transverse section of a partial circumference of a Larix gmelinii var. japonica branch, which includes the rhytidome (R), periderm (Pe), secondary phloem (Sp), vascular cambium (Vc), and secondary xylem (X). There are some developed fusiform resin cavities (Rc; arrows) containing oleoresin in the rhytidome. The fusiform shape of the resin cavities and the central crack of the rhytidome are probably caused by the tangential stress on this part owing to the secondary dilatation growth of the branch. Scale bar 5 mm