FIG. 13 in Bark anatomy of lianescent Bignoniaceae: a generic synopsis

FIG. 13. — Secondary phloem of Tanaecium and Callichlamys: A-E, transverse sections: A-C, Tanaecium pyramidatum; A, regular phloem. Tiny sieve tubes (arrows) mostly in assemblages with parenchyma cells. Thin fiber band of up to 3 cells; B, variant phloem to the same scale as the previous photo. Semi-fibrous phloem. Note sieve tubes (arrows) much wider. Rays lignified or not in random portions; C, detail of the variant phloem. Sieve tubes (*) with one to two companion cells (yellow arrows) lying in the same corner of the sieve tube. Sieve-tube-centric axial parenchyma; D, Tanaecium tetramerum, thin fiber bands. Sieve tubes with one companion cell each (insert); E, F, Callichlamys latifolia; E, variant phloem. Sieve tubes (arrows) solitary or in short multiples. Non-fibrous phloem. Fiber bands thin; F, longitudinal tangential section. Sieve tubes (arrows) with inclined, compound sieve plates. Rays uni- to biseriate. Scale bars: A-C 100 μm; D-F, 200 μm; insert, 25 μm.