FIG. 7 in Bark anatomy of lianescent Bignoniaceae: a generic synopsis

FIG. 7. — Secondary phloem of Perianthomega vellozoi: A, regular phloem, transverse section (TS). Stratified phloem, with thin to thick fiber bands, interrupted only by rays, and alternating with axial parenchyma and sieve tubes. Rays not lignified, not even when crossing the fiber bands; B, Variant phloem, TS, nonfibrous, stratified phloem, with mostly thick fiber bands, interrupted only by rays, and alternating with axial parenchyma and sieve tubes. Rays not lignified, not even when crossing the fiber bands; C, detail of the secondary phloem, TS, Sieve tubes solitary or in multiples of two-three, with one companion cell lying on the corner. Crystalliferous parenchyma with acicular crystals around the fibers. Acicular crystals also present in other axial and ray parenchyma cells. When sieve tubes touch a ray, their companion cells stay next to the ray; D, portion of the cambium showing a storying tendency for the fusiform initials, longitudinal tangential section (LS). Part of the developing xylem showing two maturing sieve tube elements (*), and the developing xylem, with some cells with pits already; E, secondary phloem, LS, sieve tubes smaller than 500 μm (arrows). P-protein accumulated in their sieve plates. Rays very tall, higher than 1 mm. Storied tendency not lost; F, periderm, TS, phellogen (arrow) produces a thin phelloderm and evenly thin walled phellem cells. Abbreviations: se, sieve element; cp, crystalliferous parenchyma; cz, cambial zone; dp, developing phloem; dx, developing xylem; p, axial parenchyma; pd, periderm; pl, phellem; r, rays. Scale bars: A, B, E, 200 μm; C, 50 μm; D, 150 μm; F, 100 μm.