Fig. 1.

Macro- and microanatomical characteristics of the bark in six tropical tree species in the tropical rainforest of French Guiana. For each species, the macrostructural features of the bark in cross-section are presented (panel top), with the cambium at the bottom and the outer bark at the top (scale bar=1 cm) as well as three longitudinal microsections (panel bottom) of the inner bark at increasing distance from the cambium (from left to right) (scale bar=1 mm). In Pachira, Cecropia, Virola, and Simarouba (A–D), the bark presents fibers (f) organized like a trellis and enlarging rays (white arrowhead) from the cambium outward. The bark of Jacaranda (E) presents fibers (f) that are not organized like a trellis and sclereids (sc). The bark of Goupia (F) shows no fibers but a substantial amount of sclereids. Sclereids were observable whatever the position in the bark in Simarouba, Jacaranda, and Goupia (E, F) while they were observed in the outer part of the bark in Virola (C) and were absent in Pachira and Cecropia (A and B). Micrographs of Pachira and Cecropia (A and B) and Virola, Simarouba, Jacaranda, and Goupia (C, D–F) were originally published by Clair et al. (2019) and Lehnebach et al. (2019), respectively. (This figure is available in color at JXB online.)