Växtstjälken

Växtstjälken, or plant stem, is a fundamental part of most vascular plants. It serves as the primary structural support for the plant, holding up leaves, flowers, and fruits, and positioning them optimally for photosynthesis and reproduction. Stems also play a crucial role in translocation, transporting water and dissolved minerals from the roots upwards to the rest of the plant, and carrying sugars produced during photosynthesis from the leaves downwards to other parts.

The stem's anatomy is complex and varies between species. Typically, it consists of several tissues, including epidermis for protection, cortex for storage and support, and vascular tissues (xylem and phloem) for transport. Xylem transports water and minerals, while phloem transports sugars. In some plants, the stem can also be a storage organ, accumulating water or nutrients, as seen in succulents or tubers.

Stems exhibit diverse forms and functions. They can be upright, creeping, climbing, or even modified into structures like thorns or tendrils. Adventitious roots can arise from the stem, aiding in anchorage and water absorption. The growth of a stem is typically apical, extending from the shoot apical meristem, and can also increase in girth through secondary growth in woody plants, forming wood and bark. The stem is a vital component for plant survival, growth, and interaction with its environment.