tulpinile

Tulpinile are the main axis of many plants, supporting leaves, flowers and fruits while connecting the root system to the aerial parts. They act as conduits for water and minerals from the roots to the rest of the plant, and for organic compounds produced by photosynthesis to be distributed throughout. In many plants, stems can also store nutrients and, in some species, contribute to photosynthesis.

Stems vary in form and structure. They can be herbaceous, green and flexible, or woody and lignified. They are typically organized with nodes from which leaves or branches arise, separated by internodes. Growth occurs at the apical meristem at the tip (primary growth), and many perennials develop secondary growth through a cambium, increasing stem girth.

The arrangement of vascular tissue differs among plant groups. In many dicotyledons, the vascular bundles form a ring within the stem, while in monocotyledons the bundles are scattered throughout the stem cross-section. This anatomy supports the transport of water, minerals, and sugars and influences the mechanical properties of the stem.

Stems can be specialized for storage or propagation. Examples include stolons (runners) that spread horizontally above ground, rhizomes that grow underground, and tubers that are swollen storage stems. Some stems are adapted for climbing or support, using features such as tendrils or thorns.

In botany and agriculture, stem biology is important for practices like pruning, grafting and breeding. Understanding stem health, growth patterns and structural characteristics helps manage plant vigor, yield and longevity.