AMI IMAGES / SCIENCE PHOTO LIBRARY AMI IMAGES / SCIENCE PHOTO LIBRARY
Tomato stem. Coloured scanning electron micrograph (SEM) of a cross-section through the stem of a tomato plant (Solanum lycopersicum). A stem is one of the main structural components of a vascular plant. The outer layer is the epidermis, with structural (ground) tissue below that. The semi-circular structure at the centre of the stem is a vascular bundle. Within this area, the larger tubes, the xylem, carry water, and the smaller tubes, the phloem, carry nutrients. On the surface of the stem are glandular hair-like structures called trichomes. The ones with rounded ends secrete distasteful chemicals to deter pests from feeding on the plant.
Model release not required. Property release not required.