Anatomy of first-order roots in the Cyclanthaceae (Monocotyledoneae). II. Stele (excluding pericycle)

Xylem always develops within xylem fascicles, and the phloem either comprises phloem fascicles or is dispersed. Xylem and phloem fascicles may be encircled by a sheath of cells different from cells of the interfascicular tissue. The interfascicular tissue is either homogeneous, i.e., consisting of fibers, or heterogeneous, i.e., formed of fiber aggregates and a parenchymatous and (or) sclerenchymatous intrusive network. This network is interpreted as modified pith. A true pith is often present, and four kinds of true pith are recognized.