Podranea ricasoliana

Pace, Marcelo R., Marcati, Carmen R., Lohmann, Lúcia G. & Angyalossy, Veronica, 2023, Bark anatomy of lianescent Bignoniaceae: a generic synopsis, Adansonia (3) 45 (12), pp. 167-210 : 199

Podranea ricasoliana

Non-stratified phloem ( Fig. 19G, H ). Sieve tubes solitary or in multiples of 2-3 ( Fig. 19I ). Most sieve plates simple, on a transverse to slightly inclined wall. One or two companion cell per sieve-tube element ( Fig. 19I ), lying on opposite sides of the sieve tube. Companion cells in strands of two cells. Axial parenchyma constitutes the ground tissue ( Fig. 19H, I ), two cells per parenchyma strand, sometimes up to four. Course of rays straight ( Fig. 19G ). Ray dilatation seemingly absent ( Fig.19G ). Rays bi-triseriate, heterocellular mixed,with procumbent, square and upright cells intermixed across the entire ray. Rays smaller than 1 mm, except when two or more rays merge. Rays do not sclerify, not even when touching the fibersclereid clusters ( Fig. 19G, H ). Sclerenchyma composed of fibersclereids only, differentiated in the nonconducting phloem in discrete, evenly distributed clusters. Non-storied. In young stems, pericyclic fibers forming a ring of discrete strands. Multiple periderms (rhytidome), reticulate ( Fig. 19G ). The phellem and phelloderm are thin walled, non-stratified ( Fig. 19G ). The phelloderm is thin, with less than three cell layers ( Fig. 19G ).

Figures

FIG. 19. — Secondary phloem of lianas of Tecomeae s.s: A-I, transverse sections:A-C, Campsis radicans; A, Overall view of the secondary phloem.Non-stratified, with scattered individual fibers; B, Detail of the secondary phloem showing individual fibers (arrows); C, detail of the secondary phloem showing the sieve tubes (arrowhead) solitary or in radial multiples of two,with one companion cell.Note the individual fiber (yellow arrow); D-F, Pandorea jasminoides; D, stratified phloem, with fibers bands alternating with sieve tubes and axial parenchyma,interrupted by the rays that do not lignify, not even when crossing the fiber bands; E, detail of the secondary phloem,with sive tubes in radial multiples (arrows), with one companion cell on their corner;F, detail of the single periderm, showing an evenly thinwalled phellem, thick phelloderm. Note the pericyclic fiber strand (arrow); G-I, Podranea ricasoliana; G, overall view of the bark. Rhytidome present, with sequent periderms (arrows) reticulate.Secondary phloem non-fibrous,devoid of fibers,with fibersclereids present in clusters (arrowheads). Course of rays straight;H, detail of the secondary phloem showing the axial parenchyma as the matrix where other cell types are found.Detail of the fibersclereid cluster (arrowhead); I, detail showing the sieve tubes in short radial multiples,with one companion cell lying on their corner (arrows). Abbreviations:cz, cambial zone;pd, phelloderm;pf, pericyclic fibers; ph, phloem; pl, phellem; x, secondary xylem. Scale bars: A, 1 mm; B, E, I, 50 μm; C, 25 μm; D, F-H, 200 μm. Fig. 19B and C by courtesy of Kishore Rajput.