Background: The extraction of salt from seawater by means of coastal solar salterns is a very well-described process. Moreover, the characterization of these environments from ecological, biochemical and microbiological perspectives has become a key focus for many research groups all over the world over the last 20 years. In countries such as Spain, there are several examples of coastal solar salterns (mainly on the Mediterranean coast) and inland solar salterns, from which sodium chloride is obtained for human consumption. However, studies focused on the characterization of inland solar salterns are scarce and both the archaeal diversity and the plant communities inhabiting these environments remain poorly described.Results: Two of the inland solar salterns (termed Redonda and Penalva), located in the Alto Vinalopó Valley (Alicante, Spain), were characterized regarding their geological and physico-chemical characteristics and their archaeal and botanical biodiversity. A preliminary eukaryotic diversity survey was also performed using saline water. The chemical characterization of the brine has revealed that the salted groundwater extracted to fill these inland solar salterns is thalassohaline. The plant communities living in this environment are dominated bySarcocornia fruticosa(L.) A.J. Scott,Arthrocnemum macrostachyum(Moris) K. Koch,Suaeda veraForsk. ex Gmelin (Amaranthaceae) and several species ofLimonium(Mill) andTamarix(L). Archaeal diversity was analyzed and compared by polymerase chain reaction (PCR)-based molecular phylogenetic techniques. Most of the sequences recovered from environmental DNA samples are affiliated with haloarchaeal genera such asHaloarcula, Halorubrum, HaloquadratumandHalobacterium, and with an unclassified member of the Halobacteriaceae. The eukaryoteDunaliellawas also present in the samples.Conclusions: To our knowledge, this study constitutes the first analysis centered on inland solar salterns located in the southeastern region of Spain. The results obtained revealed that the salt deposits of this region have marine origins. Plant communities typical of salt marshes are present in this ecosystem and members of theHalobacteriaceaefamily can be easily detected in the microbial populations of these habitats. Possible origins of the haloarchaea detected in this study are discussed.

The taxonomy of complicated native African taxa, Biscutella maritima (Brassicaceae) and annual species of Sesuvium (Aizoaceae) is discussed. The distribution of B. maritima is widened to the most of the coastal areas of NE Algeria and N Tunisia. Morphological differences with regard to other North African members of Biscutella ser. Biscutella are reported to facilitate the identification of B. maritima. We propose to accept four annual Sesuvium species (instead of the one previously accepted species, S. sesuvioides sensu amplissimo) with different distributions in Africa: S. digynum, S. hydaspicum, S. sesuvioides s.str. and S. nyasicum. A delimitation key based on morphological and carpological characters is provided. Lectotypes of S. digynum, S. digynum var. angustifolium, S. hydaspicum, S. nyasicum, Diplochonium sesuvioides (Sesuvium sesuvioides) and Trianthema polysperma (synonym of Sesuvium hydaspicum) are selected. Other discussed taxa belong to the alien elements of the flora. Atriplex semibaccata (Amaranthaceae-Chenopodiaceae) is reported as a new species for Cape Verde. Gaillardia × grandiflora (Asteraceae) is discovered as a new species for Africa found in Morocco. Prosopis velutina (Fabaceae) is collected for the first time in Northern Africa (Morocco). Mollugo verticillata (Molluginaceae) is recorded as a new species for DR Congo. Its morphology, including seed ornamentation, is discussed in reference to other similar-looking Molluginaceae. Incidence of American species Heterotheca subaxillaris (Asteraceae) in North Africa is discussed. Vernonanthura polyanthes (Asteraceae) is recorded as a naturalized invasive species in eastern Zimbabwe. It seems to be the first documented discovery of this ergasiophyte in Africa.