Centrolobium tomentosum: macro-and microscopic diagnosis of the leaf and stem

Abstract

Centrolobium tomentosum Guillemin ex Benth., Fabaceae, known as "araribá-rosa", is a large tree that is widespread throughout Brazil. The bark of its stem is used in folk medicine as an astringent and the leaves are employed as a poultice for wounds and bruises. The aim of this study was to contribute to the pharmacognostic quality control of this medicinal species through a macro-and microscopic diagnosis of its leaves and stems. Mature leaves and young stems were collected at Embrapa (Colombo, PR) and analyzed using standard microtechniques. The leaves are opposite or alternate, compound, imparipinnate, oblong-lanceolate and hypostomatic with paracytic stomata. The mesophyll is dorsiventral and the midrib is biconvex with a collateral vascular bundle in a circular arrangement. The petiolule is circular and its vascular system is composed of two major vascular bundles in the middle, with smaller bundles between them. The rachis has a structure similar to the petiole, and these parts have a sclerenchymatic sheath shaped in multiple arcs, which surrounds a collateral vascular bundle that is centrally located. The stem has a uniseriate epidermis with peripheral phellogen and a sclerenchymatic sheath composed of many arcs, which surrounds the phloem. The stems and leaves also have non-glandular and glandular trichomes, phenolic compounds and idioblasts made of calcium oxalate crystals. This manuscript has an important role in the morpho-anatomical diagnosis of the Brazilian flora.

Afforestation With Tropical N-Fixing Species in The Brazilian Atlantic Rainforest: Carbon and Nitrogen in The Soil Profile

“…A similar vertical STN and 15 N distribution in the soil pro le was observed across species with a slight tendency towards 15 N enrichment in the soil beneath P. reticulata and C. tomentosum stands.…”

“…We observed relatively 15 N-depleted N in the upper soil layers, but d 15 N values became more 15 N-enriched with depth. This pattern did not follow until deeper layers but only at intermediate depths.…”

“…Vertical changes in d 15 N values were around ~2‰ under P. reticulata, approximately two times more than C. tomentosum and H. courbaril stands.…”

“…The PCA (91.7% explanation of the data variability) showed a direct association between soil C and N stocks, and a negative correlation to PC1. The isotopic fractionation of 13 C and 15 N is indirectly correlated to soil C:N ratio indicated by the arrows in opposite directions (Fig. 5).…”

“…or d15 N = (R sample -R reference )/R reference where R sample =13 C /12 C or15 N/14 N ratio of the sample and R reference = 13 C/12 C or15 N/ 14 N ratio of the reference samples To distinguish the proportion of C derived from the previous pasture (C 4 vegetation) and from the current forest stands (C 3 vegetation) we used the equation proposed by Vitorello et al (1989): %C-C 4 = [(d-d a )-( d p -d a )]*100, where d = natural d 13 C abundance in the samples; d a = natural d 13 C abundance in the soil samples without C 4 plant residue (Secondary forest from Vicente et al (2016) used as reference); d p = natural d 13 C abundance of the pasture plant material (-12.65‰). Lastly, the following equation was used to obtain the % of the C 3 carbon: %C -C 3 =100 -%C-C Data analysis Considering the study site has no statistical design and no ll requirements for parametric analysis, our data was also submitted to descriptive analysis and comparison by Con dence Interval (p<0.05) by Student's T-test (Rmisc package, Hope 2013) through R software (R Core Team 2019).…”