Adenium obesum, (FORSSK.) ROEM. & SCHULT.

Romero, Giovanna E., 2022, Stem and caudex anatomy of succulent plant species, Adansonia (3) 44 (10), pp. 81-90 : 84

ADENIUM OBESUM (FORSSK.) ROEM. & SCHULT.

Stem cortex has sparse chloroplasts in the outer cells; laticifers are found throughout it and some druses occur in the inner part. Vascular cambium is visible. Wood is formed by some vessels, fibers, and parenchyma cells in the axial matrix. Rays are multiseriate. There are bicollateral bundles ( Fig. 1A ). Pith has laticifers and a small number of druses throughout it.

Caudex cortex has sparse laticifers and amyloplasts ( Fig. 1B ). Cortex cells are proliferating. Wood is fibrous. Axial system is formed by: vasicentric parenchyma cells with mostly scalariform pitting, thin cell wall libriform fibers ( Fig. 1B, C ). Rays are uniseriate. Few laticifers are located intrusively between ray parenchyma cells. Pith has large parenchyma cells.

Figures

FIG. 1. — Transverse sections of stems and caudices, unless otherwise noted: A-C, Adenium obesum (Forssk.) Roem. & Schult.; A, stem, bicollateral bundle; B, caudex, cortex laticifers and fibrous wood; C, caudex, fibrous wood, thin-walled libriform fibers, tangential section; D-F, Ceropegia africana R. Br.; D, stem, bicollateral bundles;E, stem,extraxylary gelatinous fibers;F, caudex,conjunctive tissue,parenchyma cells are proliferated in wood; G-I, Momordica rostrataZimm; G, stem, wood; H, caudex, wood; I, caudex, conjunctive tissue bordered by secondary phloem. Abbreviations: bc, bicollateral bundle; l, laticifer; p, parenchyma cells; gf, gelatinous fibers; ct, conjunctive tissue; pw, parenchymatous wood; fw, fibrous wood; sp, secondary phloem. Scale bars: 50 µm.