FIG. 12 in Bark anatomy of lianescent Bignoniaceae: a generic synopsis

FIG. 12. — Secondary phloem of the Fridericia­Xylophragma clade: A-D, transverse sections; A, Fridericia samydoides, overall view of the phloem wedge, with fibrous phloem, and sieve tubes with a tangential arrangement; B, Fridericia chica variant phloem. Semi-fibrous phloem, with U-shaped fiber bands. Sieve tubes (*) with one or more companion cells lying at the same side of the sieve tube. Rays lignified or not in different portions across the phloem. Radial rows of axial parenchyma sometimes lignify (yellow arrow); C, Fridericia nigrescens variant phloem. Fibrous phloem, sieve tubes in tangential arrangement. Sieve-tube centric axial parenchyma. Axial parenchyma can also form narrows bands across the variant phloem (arrows); D, Xylophragma myrianthum variant phloem. Fibrous phloem. Sieve tubes (*) in tangential arrangement. Sieve-tube-centric axial parenchyma; E, Xylophragma myrianthum tangential section of variant phloem. Uniseriate rays. Sieve tube element (*) with inclined compound sieve plates; F, Fridericia chica radial section of variant phloem. Heterocellular rays, with upright, square, and procumbent cells mixed. Sieve tubes (*) with compound sieve plates with many areas. Scale bars: A, 1 mm; B, D, 100 μm; C, E, F, 200 μm.