Jaramillo de Ibiza
A species belongs to the cruciferous family and is found in the Ibero-Balearic region. It has a distinctive leaf morphology, with some populations exhibiting very fleshy and thickened leaves. While this might suggest a process of speciation, recent studies have revealed that there is no genetic isolation; rather, it is a result of natural phenotypic variability.
Distribution
This species is endemic to the Iberian-Balearic region, with small populations present in the Xàbia area on the northern coast of Alicante and across most of the satellite islets of Ibiza and Formentera, as well as several islets of the Cabrera Archipelago and the eastern and southern coast of Mallorca.
Habitat
It grows along the coast, typically found on small islets, rocks, stony slopes, scrubland and roadsides, on limestone substrate, sometimes sandy. Despite being a coastal species, it does not occupy the first line of coastline but occurs in clearings of woody vegetation near the sea. It prefers nutrient-rich soils, particularly in areas with colonies of seabirds, and thrives in nitrohalophilic communities.
Conservation
Subpopulations of Diplotaxis ibicensis range from a few dozens to tens of thousands of individuals, with strong demographic fluctuations from year to year. The primary threat to these populations is urbanisation, especially for mainland populations. On the islets, the introduction of herbivorous vertebrates, such as goats, rabbits and possibly rats, poses a significant threat. However, the plant tends to thrive in habitats with some degree of disturbance, such as seabird colonies, forest roadsides, and areas frequented by humans. Conversely, the cessation of such disturbances can lead to a significant decline in populations due to the proliferation of woody vegetation. Seeds from both the Valencia and Baleares populations are preserved in various germplasm banks.
Image description
The seeds of this species are minute, with a diameter of less than one millimetre. The scanning electron microscope image shows a ventral view of the seed, which is ovoid or ellipsoid in shape with rounded ends. The outer covering, known the testa, has a reticulate or finely honeycombed texture, with small reliefs forming a pattern of irregular cells. This ornamentation is visible only under the magnification provided by this type of microscopy.