Mª Ángeles Alonso

New insights into seminal and stomatal morphology and their contribution to the taxonomy of the Old World succulent perennial Salicornioideae

Seminal and stomatal morphology of three succulent halophyte genera (Sarcocornia, Halocnemum and Arthrocnemum) around the Mediterranean basin and surroundings areas were investigated. Scanning electron microscopy (SEM) investigations showed well-different seminal coat ornamentations among the studied taxa. Both Arthrocnemum macrostachyum and Halocnemum strobilaceum do not show trichomes. Conversely, the species Sarcocornia perennis and S. fruticosa can be easily identified by the presence of long curved hairs against papillae or short conic hairs, respectively. Because most of the herbarium vouchers of Sarcocornia lack seeds, and thus the permanency of seeds on plants is quite short, an alternative vegetative character as stomata was also studied using SEM and light microscope. The detailed stomatal morphological features were analysed for the first time to infer taxonomic relationships among these perennial halophytes. Stomata are constantly paracytic for the four studied species, but two morphotypes were identified related to the level arrangement of guard cells, named as sunken and prominent stomata, respectively. Sunken stomata are found in A. macrostachyum, H. strobilaceum and S. fruticosa, whereas prominent stomata are only characteristic for S. perennis. Besides, we have found somehow relationships among the ecology of these plants based on the frequency of floodings and the observed morphology and density of stomata. Nonetheless, each observed morphotype is a stable character, without any influence of climate or environmental conditions. As a result, seminal coat ornamentation and stomata morphology are the two most reliable characteristics for discriminating Mediterranean halophytes taxa, especially related to Sarcocornia taxa.

A new infraspecific arrangement of Teucrium thymifolium (Lamiaceae), an aggregate endemic to the Iberian Peninsula

Abstract In the framework of our studies on Lamiaceae from the eastern Iberian Peninsula, for the forthcoming fourth volume of Flora valentina, a new infraspecific arrangement is proposed here for the Iberian endemic Teucrium thymifolium. Besides the type subspecies, T. thymifolium subsp. thymifolium, which is widely distributed through the eastern Iberian Peninsula, two new nomenclatural combinations are established: (i) T. thymifolium subsp. fraternum (Pau) M.B. Crespo, M.A. Alonso & Mart.-Azorín (= T. terciae), for the thermophilous populations growing in SE Murcia province, and (ii) T. thymifolium subsp. hervieri (Briq. & Debeaux) M.B. Crespo, M.A. Alonso & Mart.-Azorín, for Subbaetic inland populations from where the provinces of Albacete, Jaén and Granada come into contact. Nomenclatural types and data on distribution and ecology are reported for all accepted subspecies, including the designation of a lectotype for T. thymifolium subsp. hervieri. Furthermore, relationships of the latter to the recently described T. moleromesae Sánchez Gómez et al. are briefly discussed, both taxa being treated here in synonymy.

Taxonomic relationships in the Hypericum ericoides aggregate (H. sect. Coridium, Hypericaceae)

A taxonomic revision of the Hypericum ericoides aggregate is presented based on morphological characters. This aggregate is endemic to the western Mediterranean basin and is currently included in H. sect. Coridium. Light microscopy and scanning electron microscopy techniques were utilized to check the diagnostic value of several characters that were neglected or overlooked in previous works. As a result, four wellcharacterized taxonomic entities are accepted: Hypericum ericoides L., H. hispanicum (Pau) M.A. Alonso, Agulló, J.L. Villar, Juan & M.B. Crespo comb. nov. [= H. robertii var. hispanicum Pau], H. maroccanum (Maire & Wilczek) Rivas Mart. [= H. ericoides subsp. maroccanum Maire & Wilczek], and H. robertii Coss. ex Batt. & Trab. For each one, the data on morphology, ecology, and distribution are reported. Nomenclatural types are also included, and an epitype for H. ericoides is designated. Hypericum robertii, a plant supposed to be restricted to Tunisia, is reported from eastern Algeria.