This Mediterranean plant emerges from April to July in cracks in walls, roofs and even holes in the bark of trees. Widely used for its medicinal qualities, its generic name is Latin for navel, due to the shape of its leaves, and specific epithets of its name refers to the fact that it lives in the rocks. In this case it is not a cultivated plant, but spontaneously, as in the case of the Alcázar, usually grows on the trunks of large trees and magnolias. This situation reminds us of two very important questions: The first is that the gardens are populated not only by military arranged plants but also for unexpected or fleeting tenants. Landscapers as Gilles Clement suggest, through concepts like the garden in motion, the introduction of this natural creative genius, of these unforeseen opportunities, in our gardens. The second issue that arises the presence of the Navelwort, is that trees are not only a species, but an ecosystem that supports, sometimes in a parasitic way, others in perfect symbiosis, many other plant or animal species.