Comparative anatomy of the bark of stems, roots and xylopodia of Brosimum gaudichaudii (Moraceae).

摘要

Brosimum gaudichaudii occurs in the Atlantic and Amazon forests, and is the only species of Brosimum commonly found in Cerrado vegetation. It is of pharmaceutical interest due to the large accumulation of furocoumarins such as psoralens in the bark of roots and xylopodia. This work describes the bark anatomy of stems, roots, and xylopodia of B. gaudichaudii collected in cerrado area of Distrito Federal, Brazil. Although the external bark morphology of stem and subterranean system are different, anatomically they are similar, with both having wavy and fused rays at the outer region of the phloem and a gradual transition between pervious (non-collapsed) and collapsed phloem. The stem and bark periderms have three to seven layers of cells. The bark of younger stem regions is different from the bark of older parts of the stem. Younger stem parts have higher abundance of laticifers in the phloem, and gelatinous fibres arranged in bundles. Compared with the younger regions, older stems have fewer laticifers and the gelatinous fibres are scattered in the phloem. The root and the xylopodium bark are structurally similar to each other, with a higher abundance of laticifers than stems. Starch was found in the roots, but not in stems.