Rhus succedanea grows in the warm districts in Japan, and is found in large quantities especially in Kyushu. I have studied the anatomical structure of the leaves of this plant, and especially the distribution of the resin canal. In the leaves of this tree, in each fibro-vascular bundle which has ordinarily a large resin canal in the phloem and which stands as a rule at the inner side of the group of bastfibre, but the developed fibro-vascular bundle has moreover smaller resin canals close by the cambium. These resin canals run parallel to the fibro-vascular bundles in any part, and those fibro-vascular bundles in the lateral veins branch off from those in the common petiole, and those in the veinlet from those of the lateral vein. A great many resin canals are found in the phloem of the common petiole, but in the lateral vein and veinlet there is only one resin canal.
In an adult leaf, resin canals are found in the pith of the pulvinus and are also found in the bigger part of the veins too, but especially there are many resin canals in the pulvinus of the common petiole. In this part the resin canals are found at the periphery and inner part of the pith. Those at the inner part are very few, but at the periphery there are comparatively numerous resin canals, and the cross section sometimes much larger than that of the resin canals in the phloem. The resin canals in the phloem of the common petiole are most numerous at the middle·part of the first internode, and by and by the number diminishes as the internode becomes smaller. The petiole of the leaflets has four relatively large resin canals and any number of smaller ones, but there is only one at the end of the end of the midrib of the leaflets.
In the petiole of the cotyledon, there are only two resin canals, but four in the petiole of the leaflets of the first common leaves of seedlings. All these resin canals enter into the midrib, but their number diminishes gradually, untill only one of them remains at the end of the midrib. While other species of Rhus have a great number of the trichome on their leaves, we can find only a very few of this species, and then only on the cotyledon, : the midrib of the common leaves of seedlings and on the scally leaves of the winter buds of the adult plant.

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