Section of a Sambucus branch with a lentil on the bottom left -Section of Ballota: the support material is an angular collenchyma – Section of a liana branch: the support material is a round collenchyma – Section of Malus : note the secondary structure of the trunk – Section of a Euphorbia branch: note the width of the part constituting the cork – Section of Fraxinus trunk – note the secondary structure of the trunk.
© Giuseppe Mazza