ABSTRACT Pterodon (Fabaceae) species known as “sucupira-branca” are traditionally used in Brazilian medicine. This South American monophyletic genus has species delimitation problems. To separate the recognized Pterodon species we described the wood anatomy of P. abruptus, P. emarginatus, P. pubescens, hybrid (between P. emarginatus and P. pubescens) and P. apparicioi, the latter two for the first time. Wood anatomical studies were undertaken, and qualitative and quantitative features statistically tested. Qualitatively the species are very similar, but in most quantitative features, differences were observed, especially axial parenchyma quantity and type. Pterodon abruptus was easily separated by high density narrow vessels allied to a low area of axial parenchyma but with confluent almost forming bands. Hybrid was more similar to P. emarginatus and had a significantly greater axial parenchyma area than other Pterodon species. PCA analysis separates only P. abruptus. Cluster analysis using qualitative and quantitative data were able to separate P. abruptus and P. apparicioi from the other species. Vessels, ray and axial parenchyma features enable to clarify the distinction in identification key.

SUMMARY: Studies on root wood anatomy are scarce, mainly due to the lack of commercial interest and the difficulty to collect. In Brazilian Cerrado, local craftsmen use root wood for marquetry, the manufacture of such small items as lampshades or ornaments, and table bases. However, taxonomy based on root wood can serve as a guide toward the conservation and management of tree stocks in urban environment. Therefore, we herein describe the root wood anatomy of 14 tree species that occur in the Brazilian Cerrado. To accomplish this, we studied samples from main sinker root, at a depth of about 20 cm, from 37 trees aged 5 to 10 years. Anatomical procedures followed the standard techniques for preparation and analyses of wood samples. We used stem or branch samples from other studies to carry out anatomical description and comparison. However, we encountered some problems, such as: difficulty to distinguish growth rings, sample processing and, in some cases, sample description, since quantity, distribution and type of axial parenchyma differed substantially from that of the main stem. Nonetheless, we did find a variation in the presence/absence of septate fibers among the samples, and noted differences in ray composition.

RESUMEN: Los estudios sobre la anatomía de la madera de raíz son escasos, principalmente por la falta de interés comercial y la dificultad de recolección. En el Cerrado brasileño, los artesanos locales utilizan la madera de raíz para la marquetería, la fabricación de objetos pequeños como pantallas de lámparas o adornos, y la base de la mesa. Sin embargo, la taxonomía basada en la madera de raíz puede servir como una guía para la conservación y el manejo de las reservas de árboles en entornos urbanos. Por lo tanto, se describió la anatomía de la raíz de la madera de 14 especies de árboles que se encuentran en el Cerrado brasileño. Se estudiaron muestras de la raíz principal, a una profundidad de aproximadamente 20 cm, de 37 árboles de 5 a 10 años. Los procedimientos anatómicos siguieron las técnicas estándar para la preparación y el análisis de muestras de madera. Se utilizaron muestras de tallo o rama de otros estudios para llevar a cabo la descripción anatómica y la comparación. Sin embargo, se encontraron algunos problemas, tales como: los anillos de crecimiento difíciles de distinguir; además, era problemático procesar la muestra y, en algunos casos, describirla dado que la cantidad, distribución y tipo de parénquima axial difería sustancialmente de la del tallo principal. No obstante, se encontró una variación en la presencia/ausencia de fibras septadas entre las muestras, y también diferencias en la composición de los radios.

Este estudo investigou a ocorrência de camadas de crescimento em 48 espécies representativas de cerrado no estado de São Paulo, Brasil. Amostras foram obtidas da porção basal de ramos caulinares mais desenvolvidos. Foram caracterizados os marcadores de crescimento, bem como foi descrita a estrutura das camadas de crescimento. As camadas de crescimento apresentaram-se mal definidas em 33% e bem definidas em 61%, sendo ausentes em 6% das espécies analisadas. Várias características anatômicas foram utilizadas como marcadores de crescimento, tais como: fibras de paredes espessas; fibras achatadas radialmente, zonas fibrosas; raios distendidos; faixas marginais de parênquima axial; linhas de parênquima marginal; e proximidade das linhas de parênquima escalariforme. Diferentes marcadores podem ocorrer em uma mesma espécie. Variações na distribuição do parênquima axial nas camadas de crescimento em Vochysia cinnamomea, Qualea multiflora, V. rufa and V. tucanorum, bem como variação na distância das linhas de parênquima axial ao longo dos raios dentro das camadas de crescimento em Annona coriacea, A. crassiflora, Diospyrus hispida e Roupala montana são aqui reportadas pela primeira vez. A fenologia e o hábito das espécies foram aspectos importantes relacionados tanto com a presença e nitidez das camadas de crescimento no lenho quanto com as variações dentro dessas camadas.

Growth ring occurrence was investigated in 48 representative species of cerrado in the state of São Paulo, Brazil. We characterized growth ring markers and described the growth layer structure of the basal portion of the most developed stem branches in woody plants. Growth rings were poorly defined in 33%, well defined in 61% and not discernable in 6% of the species studied. Various anatomical features were used as growth markers, such as: thick-walled latewood fibres; radially flattened latewood fibres; fibre zones; distended rays; marginal bands of axial parenchyma; marginal lines of parenchyma; and closeness of the narrow bands of scalariform parenchyma. In a single species, different growth ring markers often occurred together. Within growth layers, variations in the anatomical features were observed. Variations in the axial parenchyma distribution within growth rings in Vochysia cinnamomea, Qualea multiflora, V. rufa and V. tucanorum, wood are here reported for the first time. Variation in the distance of the axial parenchyma in narrow bands along the rays within growth layers in Annona coriacea, A. crassiflora, Diospyrus hispida and Roupala montana wood is also reported. Phenology and habit of the studied species were important aspects related to both growth ring presence and distinctness as well as to the anatomical features' variations within growth layers.