Otatea carrilloi (Fig. 6)

Material examined: — MEXICO. Chiapas: Tonalá, La Sepultura, vicinity of Raymundo Flores, 16°1’57.86”N, 93°36’12.20”W, 649 m, 15 February 2022, E . Ruiz-Sanchez et al. 730 (IBUG!).

Culm anatomy description: —Culm hollow, the lacuna occupying> 50% of the total diameter. Epidermis with a layer of axially elongated lignified cells, 14 µm length, with frequent squared to rectangular silica bodies on top (Fig. 6B). Cortex with 2 layers of narrow thick-walled rounded cells, followed by 3–4 layers of wider thinner-walled rounded cells (in total, 5–6 layers, 61 µm length; Fig. 6B). Vascular bundles in 10–11 alternating cycles (Fig. 6A). Peripheral, transitional, and central vascular bundles surrounded by a sclerenchyma sheath defining their contour (Figs. 6C–E). Cell wall of fiber sheath weakly lignified. Ovate central vascular bundles, 439 × 451 μm; two round shaped metaxylem vessels, 100 × 110 μm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 91 × 120 µm; sieve tubes 18 × 23 µm (Fig. 6E). Frequent amorphous silica bodies embedded along the periphery of vascular bundles occupying cellular spaces covering a mean area of 90 µm 2.