| The presence of tanniferous and chlorenchyma cells in the stem has never been described previously. |
| As seen in transverse sections stems in all species are composed of a single epidermis with one to four layers of chlorenchyma cells. |
| Stems consist of a single layer of epidermis, one to four chlorenchyma layers, one to seven layers of cortical cells and a bicollateral bundle with pith in the center. |
| Chlorenchyma has smaller isodiametric cells than the storage parenchyma, it has many chloroplasts. |
