Dolichandra

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 : 194-195

XIV. Dolichandra clade

TAXONOMIC INFORMATION. — This clade contains a single genus, Dolichandra , with multiple dissected phloem wedges in transversal section. Dolichandra currently includes species from four previously recognized genera (see Fischer et al. 2004; Table 2 ), Dolichandra , Macfadyena A.DC. , Melloa Bureau , and Parabignonia Bureau ex K.Schum.

TOTAL NUMBER OF SPECIES IN THIS CLADE. — 9 species ( Fonseca et al. 2017).

STUDIED SPECIES. — Three species, Dolichandra quadrivalvis (Jacq.) L.G.Lohmann , Dolichandra unguiculata (Vell.) L.G.Lohmann , and Dolichandra unguis-cati (L.) L.G. Lohmann.

Regular phloem

Thin to thick fiber bands, without assemblages.

Variant phloem

The variant phloem of Dolichandra is nearly identical to that of the Multiples of four s.s. clade.In fact,the sieve tubes and phloem parenchyma arrangement, the sieve plate type, the presence of crystals, and the number of cells between fiber bands is alike in both clades ( Fig. 16 A-C). The presence of sieve elements of two distinct diameters (40 µm and 15 µm in average) tending to gradually go from wide to narrow diameter in subsequent bands ( Fig. 16D ) is similar to that found in Amphilophium . Another similarity with Amphilophium is the storied structure ( Fig. 16E ); however, the storied structure in Dolichandra is found both for axial and radial elements ( Fig. 16E ). A further remarkable difference from the Multiples of four s.s. clade is the non-lignification of the limiting rays ( Fig. 16 A-C), that tend to divide, compress, and dissect the phloem wedges ( Fig. 16A, C ). The crystalliferous parenchyma in Dolichandra bears acicular crystals, which are also found in the rays ( Fig. 16D, F ).

Periderm

A single periderm is formed.The phellem is stratified,with alternating thin and thick-walled cells.The phelloderm is non-stratified, thin, with less than three cell layers.Lenticels were not observed.

Figures

FIG. 16. — Secondary phloem of Dolichandra: A-D, transverse sections; B, Dolichandra unguiculata. All other photos are from Dolichandra unguis­cati; A, limiting rays non-lignified, tend to expand and divide (arrows), non-fibrous phloem. Thin fiber bands; B, non-fibrous phloem, sieve tubes in short radial multiples. Limiting rays non-lignified; C, pith also undergo divisions, uniting to divisions at the limiting rays (arrowheads). Nonconducting phloem collapsed; D, detail of the conducting variant phloem. Sieve tubes (arrows) with one or two companion cells.Acicular crystals abundant; E, tangential section. Storied structure in both axial and ray cells; F, radial section. Sieve tube elements with compound sieve plates (arrow). Abbreviations: cz, cambial zone; pi, pith. Scale bars: A, 200 μm; B, E, 150 μm; C, 500 μm; D, 50 μm; F, 100 μm.