Antecedentes y Objetivos: Uno de los enfoques más recientes para delimitar especies vegetales es el uso de caracteres anatómicos de la madera en representantes leñosos que ha sido poco explorado en taxones mexicanos. El género Forestiera (Oleaceae) es un ejemplo de esto, pues solo se ha descrito la madera de dos de las 12 especies distribuidas en México. Con el objetivo de contribuir al conocimiento de la anatomía de la madera del género, así como a la búsqueda de caracteres anatómicos que discriminen entre sus especies, en el presente estudio se describe la anatomía de la madera de ocho especies de Forestiera distribuidas en México con un enfoque sistemático. Métodos: Se analizaron 42 muestras de madera de ocho especies, provenientes de tres individuos por especie en 14 sitios de colecta. El material se procesó con microtecnia convencional para obtener variables anatómicas cualitativas y cuantitativas. Estas fueron evaluadas con estadística multivariada para determinar cuáles son importantes para formar grupos de especies en Forestiera. Resultados clave: Algunos atributos anatómicos reportados anteriormente coinciden con los observados en este trabajo. Sin embargo, hay diferencias como la porosidad semianular y la delimitación de marcas de crecimiento sin presencia de parénquima marginal. Los análisis formaron grupos de especies dados por el diámetro de vasos de la madera temprana, longitud de elementos de vaso y fibras, diámetro de las fibras, tipo de radios, abundancia del parénquima marginal y tipo de cristales en los radios. Con base en la anatomía de la madera, se propone una clave taxonómica para identificar las especies estudiadas. Conclusiones: Mediante los análisis empleados se contribuye al conocimiento de la anatomía de la madera de Forestiera; además, se reconocen caracteres que permiten distinguir grupos de especies. Futuros estudios confirmarán su valor taxonómico.

Lignin is one of the most studied and analyzed materials due to its importance in cell structure and in lignocellulosic biomass. Because lignin exhibits autofluorescence, methods have been developed that allow it to be analyzed and characterized directly in plant tissue and in samples of lignocellulose fibers. Compared to destructive and costly analytical techniques, fluorescence microscopy presents suitable alternatives for the analysis of lignin autofluorescence. Therefore, this review article analyzes the different methods that exist and that have focused specifically on the study of lignin because with the revised methods, lignin is characterized efficiently and in a short time. The existing qualitative methods are Epifluorescence and Confocal Laser Scanning Microscopy; however, other semi-qualitative methods have been developed that allow fluorescence measurements and to quantify the differences in the structural composition of lignin. The methods are fluorescence lifetime spectroscopy, two-photon microscopy, Föster resonance energy transfer, fluorescence recovery after photobleaching, total internal reflection fluorescence, and stimulated emission depletion. With these methods, it is possible to analyze the transport and polymerization of lignin monomers, distribution of lignin of the syringyl or guaiacyl type in the tissues of various plant species, and changes in the degradation of wood by pulping and biopulping treatments as well as identify the purity of cellulose nanofibers though lignocellulosic biomass.

The anatomical traits associated with water deficit are also observed in plants growing in poor soils. The species may resist water deficit through three main strategies: escape, avoid or tolerate. The Pedregal de San Ángel Ecological Reserve (REPSA), Mexico, is an environment with low nutrient soil and low water availability. It is set on the basalt formation derived from the Xitle volcano eruption. The main vegetation type is characterized as xerophytic shrub. Thus we expect that species growing in this community will show leaf xeromorphic traits and may have any of the three response strategies. We analyzed the foliar anatomy of 52 species of the Asteraceae family at the REPSA because it is the most abundant angiosperm family in the site, showing a wide variety of growth forms and anatomical variation. The foliar anatomies of the studied Asteraceae were highly variable as well as their quantitative traits as revealed by principal component analysis. This agrees with previous studies that found great anatomical variation within the family. Leaves have multiple layered palisade parenchyma and parenchyma bundle sheaths and could not be categorized as xeromorphic because they possess mesomorphic leaf features as simple lamina, single-layered epidermis, and soft large-size glabrous leaves with high specific leaf area. The combination of mesomorphic and few xeromorphic foliar traits with other characters at the genus and tribal level probably has been essential in Asteraceae to colonize various environments, including those with low water and nutrient availability.