At the Marimurtra Botanical Garden, we often invite visitors to look up beyond the flowerbeds. Among the branches of our specimens, a fascinating biological dynamic develops that we popularly call “plant friendship“, but which in strict botanical terms responds to the concept of epiphytism.
A brilliant evolutionary adaptation
Epiphytism is not only found in a taxonomic group in itself, but is a life strategy that has evolved independently in some 80 families of vascular plants. This adaptation allows certain species to colonize the arboreal stratum to guarantee a resource that is often scarce on the floor of jungles and forests. By placing themselves on the branches, these plants avoid direct competition for space and light, transforming the bark of the trees into their ecological niche.
With all this, it is essential to debunk a common myth: epiphytes are not parasites. Unlike the latter, epiphytes do not develop haustoria (roots that penetrate the host’s tissues to extract nutrients), but instead use the tree exclusively as a support to be higher up. It is a relationship of commensalism where the epiphyte obtains a clear benefit (+) while the tree receives no harm (=).
Since they do not have access to the ground, these plants have developed sophisticated mechanisms to capture water and nutrients:
- Bromeliads (such as the air carnation): many Tillandsia species possess trichomes, highly specialized hairs, which absorb atmospheric humidity and protect the plant from extreme insolation.
- Orchids: many have developed the velamen, a spongy tissue in the aerial roots that acts as a membrane capable of retaining rainwater almost instantaneously.
- Ferns and other groups: species such as Platycerium accumulate plant remains at their base to create their own micro-soil in full suspension.
During your visit to the Garden, you will be able to observe this phenomenon in its maximum expression everywhere. On the branches of trees and shrubs, several specimens of Tillandsia coexist in perfect harmony, creating a silver tapestry that is a living witness to this “plant friendship”.
To delve deeper into this concept, we recommend finding our poster on plant friendship and our nomadic blackboard, where we explain the structural differences between terrestrial, aquatic and these fascinating “aerial” plants.
