Limonium mucronatum: plant communities and cytogenetic characterization of an endemic of the Moroccan Atlantic Coast

Limonium mucronatum (L.f.) Chaz. (Plumbaginaceae), a strict endemic of Morocco, has a restricted range in the littoral zone between Rabat and Tan Tan (Draa valley). This coastal region at the junction of Mediterranean, Canary and Saharan influences is of considerable biogeographical interest. However, little information exists on L. mucronatum communities and its relationship with bioclimatology or chromosome polymorphisms, which may have an impact in the context of plant conservation. In this study, we analysed L. mucronatum communities and performed a cytometric and karyological characterization of this rare species. Results showed two plant communities associated with this species related to a latitudinal and bioclimatic gradient along the surveyed region. Our study provided for the first time new data regarding nuclear DNA amount and about the numbers, positions and organization of 45S rDNA loci in L. mucronatum. Remarkably, cytogenetic analyses revealed homogeneous ploidy across all studied populations with all individuals with 2n¼12 chromosomes. The results obtained are discussed in the context of the originality of flora and the threats to L. mucronatum communities, and in the perspective of a conservation strategy for this endemic species