There are 2-3 layers of long-column-shaped palisade tissue under the upper epidermis, and there are a great number of mechanical tissues which made up of vascular bundle sheath .

• 上表皮下方有2-3层长柱形的栅栏组织，在主脉大侧脉外方具有由大量机械组织组成的束帽或束鞘。