Otatea acuminata AGS (Fig. 2)

Material examined: — Aguascalientes: Calvillo, Jagúey canyon, 3 km E of Piedras Chinas, 1.5 km N of El Zapote de la Labor, 21°58’46.99”N, 102°39’23.2”W, 1969 m, 9 June 2020, E . Ruiz-Sanchez & M. A . García-Martínez 652 (IBUG!) .

Culm anatomy description: —Culm solid. Epidermis with a layer of axially elongated lignified cells, 12 µm length, with axially elongated silica bodies (Fig. 2B). Cortex with 2 layers of narrow thick-walled cells followed by 3–4 layers of thinner-walled rounded cells (5–6 layers in total, 70 µm length; Fig. 2B). Vascular bundles in 8–9 alternating cycles (Fig. 2A). Peripheral, transitional, and central vascular bundles surrounded by a sclerenchyma sheath defining their contour (Figs. 2C–E). Elliptical central vascular bundles, 488 × 444 μm; two round shaped metaxylem vessels, 98 × 106 µm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 119 ×136 µm; sieve tubes 24 µm × 23 µm (Fig. 2E). Scarce amorphous silica bodies embedded along the periphery of vascular bundles occupying cellular spaces covering a mean area of 70 µm 2. Sporadic conical silica bodies across the ground tissue occupying intercellular spaces covering a mean area of 30 µm 2.