Pandorea jasminoides

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

Pandorea jasminoides

Stratified phloem ( Fig. 19D ), marked by the alternation of fiber bands, interrupted only by the rays, with areas of sieve tubes and axial parenchyma ( Fig. 19D ). Conducting phloem composed of sieve tubes solitary or in multiple of 2-3 ( Fig.19E ), intermingled by axial parenchyma cells ( Fig. 19E ). Sieve plates varying from almost transverse end walls and simple sieve plates, to inclined with 4-5 sieve areas. One companion cell lying on the corner of the sieve tube ( Fig. 19E ) or two companion cells, each on opposite sides of the sieve tube ( Fig. 19E ). Companion cells in strands of 2-4 cells. Axial parenchyma diffuse ( Fig. 19D, E ), abundant, in strands of four cells. Course of rays straight ( Fig. 19D ). Rays bi- to triseriate, heterocellular mixed, with procumbent, square and upright cells intermixed across the entire ray. Rays taller than 1 mm, as seen in tangential section. Rays slightly dilated in the outermost portions of the nonconducting phloem. Rays do not sclerify, not even when touching the fiber bands ( Fig. 19D, E ). Sclerenchyma composed of fibers, polygonal to rectangular in shape ( Fig. 19D, E ). Fibers in tangential bands of 2-3 cells, interrupted by the rays ( Fig. 19D, E ). Non-storied. Nonconducting phloem marked by empty sieve elements and companion cells, collapsed. Cell expansion common, dilatation of rays, no further sclerification seen. Pericyclic fibers forming a ring of discrete strands before a remaining cortex. Single periderm, phellem non-stratified, with evenly thin-walled cells, phelloderm non-stratified, thick, with three or more cell layers ( Fig. 19F ).

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.