The Diploschistes diacapsis, also call Diploschistes steppicus, usually grows to total sun applied on carbonated or chalky substrates. In Majorca it lives on very poor argillaceous grounds with little rains and a strong insolation. Sights by far these lichens seem outcrops of calcareous rocks excelling millimeters over the earth layer.
A lichen is the symbiotic association between a fungus and an alga. The apotheciums are the reproductive organs of the symbiont fungus called micobiont. In each apothecium are small bags called asci, where the greenish or brownish ascospores in number of 8 by each ascus. After an abundant rain the asci reach the maturity quickly, become very turgescent and explode, releasing the ascospores explosively to the air so that they arrive more far possible.
The other component of the lichen receives the name of ficobiont and is formed by unicellular algae that lives in very little number in the ground. In conditions of extreme aridity the algae only can survive associate a fungus forming a lichen. After an abundant rain some cells algals are freed of the fungus and fall in the small pools where they reproduce like any alga. Its aquatic life is very brief. If the pool is dried, the alga dies. Not to be extinguished they resort to the intelligent strategy to be associated to a fungus.
When an ascospore is dispersed by the outbreak of a ascus flies more far possible helped by the wind and if it falls on a suitable humid substrate it germinates and it begins to produce a filament maze or hyphae. Nevertheless, if it soon does not find an unicellular alga with which to be associated, the fungus literally dies of starvation when needing it the carbohydrate contribution synthesized by the chlorophyll of the alga.
When there is luck and the chance causes that both simbionts are in the same point where fell the ascospore, generally a small accumulation of rainwater in the ground, as hyphae of the fungus is forming a filament maze, that is to say, the structure of the lichen, the unicellular algae are reproduced by simple cellular division and the new cells algals are placed between hyphae in intimate contact with them, as if renters of a building it was. The true symbiosis begins then. Fungal hyphae absorbs water and minerals of the ground and transfer them to the algae. These in return provide to hyphae of the fungus the carbohydrates that have elaborated from the solar light. They form because a reconciled marriage of good convenience in which both spouses remove a benefit. Really, they represent an intelligent strategy of survival of two beings who separately could not survive.
It is therefore understood the need for this lichen to be trampled, as vegetative reproduction by fragmentation of the thallus is much easier and safer than random reproduction by spores in a habitat where rains are very rare and extreme dryness prevails over most of the year.