Uncovering the Neglected Floral Secretory Structures of Rhamnaceae and Their Functional and Systematic Significance

Rhamnaceae flowers are notably recognized by their fleshy nectary. Other types of floral secretory structures have been scarcely reported for this family. Thus, the objective of the present study was to update the occurrence of these structures in the family and to contribute to the knowledge of their morphology and systematic significance. To this end, we carried out an extensive bibliographic search on the secretory structures of the family and obtained data for 257 taxa. Additionally, we presented here novel data (surface, anatomy, and ultrastructure) for six species belonging to the main clades within Rhamnaceae. The family has a wide diversity of types of mucilage-secreting structures: epidermis, hypodermis, idioblasts, cavities, and ducts. Mucilage and phenolic idioblasts are widely distributed among the floral organs. Colleters are present in all sampled species, and these are the first reports of their occurrence in floral organs of Rhamnaceae. The information obtained about the structure, secreted content, and occurrence of the secretory structures of Rhamnaceae helped us to understand the assertive folk use of its species. The absence of mucilage and the presence of resin or mucilage cavities and ducts in some taxa may have intrafamily systematic significance.

Husserl y la fenomenología de la negación

Husserl desarrolla un enfoque genético que busca dar cuenta del origen de las formas lógico-categoriales a partir de las correspondientes preestructuraciones situadas en el nivel de la receptividad sensible. Para un enfoque de ese tipo, la explicación del origen de las modalidades del juicio, en general, y la negación, en particular, plantea peculiares desafíos. El presente trabajo discute el modo en el que Husserl trata la negación, en tanto forma básica de la modalidad, tanto en el enfoque estático de Ideen I como en el enfoque genético de Erfahrung und Urteil. A fin de poner de relieve el al-cance histórico y sistemático de la concepción husserliana, se proporciona previamente una presentación general de su contexto polémico inmediato. Este viene dado por la oposición entre psicologismo y formalismo, dominante en la filosofía de la lógica alemana de fines del siglo XIX y comienzos del siglo XX.Husserl develops a genetic approach that seeks to account for the origin of the logical-categorical forms starting from the corresponding pre-structures located at the level of sensitive receptivity. For such an approach, the explanation of the origin of the modalities of judgment, in general, and negation, in particular, poses peculiar challenges. This paper discusses how Husserl treats negation as a basic form of modality, both in the static approach of Ideen I and the genetic approach of Erfahrung und Urteil. Previously, in order to highlight the historical and systematic significance of the Husserlian conception, a general presentation of its immediate polemic context is offered, especially with reference to the opposition between psychologism and formalism, dominant in the German philosophy of logic of the late nineteenth and early twentieth century.