tallos

Tallos, the plural form of the Spanish word for stem, refers to the stems of vascular plants. In botany, a tallo is the main above-ground axis that supports leaves, flowers, and fruits and connects the aerial parts to the root system. Tallos vary widely in size, shape, and function, and they may be green and photosynthetic or largely serving storage.

Structure and growth: Tallos are organized into tissues, including the epidermis, cortex, and a vascular cylinder containing xylem and phloem. They develop from apical meristems at shoot tips, enabling primary growth that lengthens the plant. In many woody species, secondary growth occurs through cambia, which thickens the stem by producing new xylem and phloem.

Nodes, internodes, and buds: The tallo bears leaves and buds at nodes, with the segments between nodes termed internodes. Some nodes house lateral shoots or flowers. Vascular arrangement can differ among plant groups, contributing to variations in strength, flexibility, and transport efficiency.

Forms and specializations: Tallos can be herbaceous (soft and green) or woody (lignified). They may be erect, climbing, or creeping. Some plants have specialized stems, such as rhizomes (underground stems), stolons or runners (horizontal above-ground stems), and tubers (storage stems). In bananas, for example, the pseudostem is formed from leaf bases rather than a true stem.

Functions and adaptations: The tallo provides mechanical support, transports water, minerals, and sugars through the vascular system, and often stores resources. Green tallos can also contribute to photosynthesis, aiding the plant’s energy production. Across plant groups, tallos display adaptations that fit their environments and life strategies.