Otatea victoriae (Fig. 13)

Material examined: — MEXICO. Hidalgo: Cardonal, Tolantongo-Metztitlán dirt road, 5 km east of the junction to the road that leads to Tolantongo, 20°37’38.1”N, 98°57’31.3”W, 1775 m, 2 February 2020, E . Ruiz-Sanchez & M. A . García-Martínez 647 (IBUG!) .

Culm anatomy description: —Culm hollow with wide lacuna occupying> 50% of the total diameter. Epidermis with a layer of axially elongated lignified cells, 15 µm length, with frequent squared to rectangular silica bodies on top (Fig. 15B). Cortex with 3–5 layers of thick-walled rounded cells, the outer layer with slightly narrower cells(48 µm length; Fig. 15B). Vascular bundles in 9–10 alternating cycles. Peripheral, transitional, and central vascular bundles surrounded by a sclerenchyma sheath defining their contour (Figs. 15C–E). Ovate central vascular bundles, 357 × 353 μm; two round shaped metaxylem vessels, 81 × 87 μm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 87 × 104 µm; sieve tubes 22 × 21 µm (Fig. 15A). Scarce amorphous silica bodies embedded along the periphery of vascular bundles occupying cellular spaces covering a mean area of 58 µm 2. Sporadic conical silica bodies across the ground tissue occupying intercellular spaces covering a mean area of 9 µm 2.