Explanation

In Cycas leaflet, transfusion tissue or hydrostereon are present on each side of the midrib in between the palisade and spongy tissue. Transfusion tissue is made up of horizontally arranged tracheids, which supply water and minerals to palisade and spongy tissue up to margins. Transfusion tissue facilitates lateral conduction of water because there in no lateral veins. Leaf of Pinus also contains transfusion tissue (needle).