The word "tree" in English means a long lived plant having obvious main stem, and growing to a considerable height and size. Thus not all trees have all the organs or parts as mentioned above. For example, most (tree-like) palms are not branched, and tree ferns do not produce bark.The word "tree" in English means a long lived plant having obvious main stem, and growing to a considerable height and size. Thus not all trees have all the organs or parts as mentioned above. For example, most (tree-like) palms are not branched, and tree ferns do not produce bark.The word "tree" in English means a long lived plant having obvious main stem, and growing to a considerable height and size. Thus not all trees have all the organs or parts as mentioned above. For example, most (tree-like) palms are not branched, and tree ferns do not produce bark.