Liana — woody climbing plants of tropical forests

Characteristics

Lianas are distinguished by stems that are long, flexible and woody. Many begin life on the forest floor and climb by twining, by using tendrils, or by leaning and scrambling over supports. Leaves, flowers and fruits are borne in the canopy, where access to light allows prolific reproduction. Common structural features include strong secondary growth that provides tensile strength and adaptations for attaching to hosts.

Ecology and role in forests

Ecologically, lianas influence tree growth, mortality and canopy connectivity. They compete with trees for light and water, can slow tree regeneration, and increase the risk of wind damage by creating bridges between trunks. At the same time, lianas supply food and shelter for many animals: their flowers, nectar and fruits feed insects, birds and mammals, and their stems and tangles provide pathways and refuges for arboreal species.

Uses and cultural importance

• Some lianas are harvested for materials such as rattan and cane used in furniture and basketry.
• Traditional societies use various lianas for ropes, construction, and medicinal purposes.
• They are also of interest in restoration and agroforestry systems where climbing species can provide food or structural diversity.

Origins and diversity

The liana habit has evolved independently in numerous plant families, so "liana" describes a growth form rather than a single lineage. Families with many liana species include Vitaceae, Fabaceae, Bignoniaceae and Apocynaceae. While most lianas occur in tropical regions, related climbing forms exist in some temperate woodlands as well.

Distinguishing lianas

Not all climbing plants are lianas: many vines are herbaceous and short-lived, whereas lianas are predominantly woody and perennial. They should also be distinguished from hemiepiphytes and parasitic climbers that have different life strategies. Because they rely on hosts to reach sunlight, lianas are integral to the three-dimensional structure of forests and are a key factor in understanding forest dynamics and conservation.

For further habitat context see general rainforest information: rainforest habitats, and for how lianas attach to hosts see tree support strategies.