‖ ˌcalamoˈdendronPalæont. [f.Gr. κάλαµος reed + δένδρον tree.] A supposed genus of fossil trees; the fruits are found along with calamites, and are supposed by many to belong to them. 1873Dawson Earth & Man vi. 131 The..Calamodendron or Reed-tree..had stems with thick woody walls.