Bamboo stem. Coloured scanning electron micrograph (SEM) of a section through a bamboo stem (Phyllostachys sp.). Vascular bundles can be seen (orange) containing xylem (larger openings) and phloem (smaller openings). The xylem transports water and mineral nutrients from the roots throughout the plant and the phloem transports carbohydrates and plant hormones around the plant. The pink fibres are woody supportive tissue. Bamboos are tropical and subtropical members of the grass family Gramineae. The stems, known as canes or culms, can reach great heights. They are widely used in construction, as these fibres form very tough structures, but are also flexible. Magnification: x80 when printed at 10 centimetres tall.