Culm anatomy of the genus Otatea (Poaceae, Bambusoideae, Bambuseae, Guaduinae) as a contribution to Mexican species identification Author García-Martínez, Miguel A. Doctorado en Ciencias en Biosistemática, Ecología y Manejo de Recursos Naturales y Agrícolas, Universidad de Guadalajara, Camino Ing. Ramón Padilla Sánchez 2000, Nextipac, Zapopan, Jalisco, 45200, Mexico. & Laboratorio Nacional de Identificación y Caracterización Vegetal (LaniVeg), Instituto de Botánica, Universidad de Guadalajara, Camino Ing. Ramón Padilla Sánchez 2000, Nextipac, Zapopan, Jalisco, 45200, Mexico. Author Terrazas, Teresa 0000-0001-7749-5126 Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico City, Mexico. Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Camino Ing. Ramón Padilla Sánchez 2000, Nextipac, Zapopan, Jalisco, 45200, Mexico. & tterrazas @ ib. unam. mx; https: // orcid. org / 0000 - 0001 - 7749 - 5126 tterrazas@ib.unam.mx Author Sánchez, Daniel Investigador por México, Consejo Nacional de Humanidades Ciencias y Tecnologías (CONAHCYT), Laboratorio Nacional de Identificación y Caracterización Vegetal, Departamento Botánica y Zoología, Universidad de Guadalajara, Camino Ing. Ramón Padilla Sánchez 2000, Nextipac, Zapopan, Jalisco, 45200, Mexico. Author Reyes, Pablo Carrillo- 0000-0001-9278-0208 pablo. creyes @ academicos. udg. mx; https: // orcid. org / 0000 - 0001 - 9278 - 0208 pablo.creyes@academicos.udg.mx Author Ruiz-Sanchez, Eduardo Laboratorio Nacional de Identificación y Caracterización Vegetal (LaniVeg), Instituto de Botánica, Universidad de Guadalajara, Camino Ing. Ramón Padilla Sánchez 2000, Nextipac, Zapopan, Jalisco, 45200, Mexico. text Phytotaxa 2023 2023-08-22 609 2 75 102 http://dx.doi.org/10.11646/phytotaxa.609.2.1 journal article 10.11646/phytotaxa.609.2.1 1179-3163 8272241 Otatea glauca ( Fig. 8 ) Material examined: — MEXICO . Chiapas : Motozintla , Km 37 of the Huixtla-Motozintla highway, 15°19’46.58”N , 92°19’25.72”W , 1141 m , 14 February 2022 , E . Ruiz-Sanchez et al. 726 ( IBUG !) . FIGURE 8. Culm cross section of Otatea glauca . A . Cross section general view. B . Fiber sheath with an amorphous silica body occupying cellular space. C . Epidermis and cortex. D . Peripheral vascular bundle. E . Transitional vascular bundle. F . Central vascular bundle. Abbreviations: co , cortex; ep , epidermis; fs , fiber sheath; mx , metaxylem; pa , parenchyma; ph , phloem; px , protoxylem; sc , sclerenchyma; si , silica bodies. Culm anatomy description: —Culm hollow, the lacuna occupying> 50% of the total diameter. Epidermis with a layer of axially elongated lignified cells, 12 µm length, with frequent rectangular silica bodies on top ( Fig. 8C ). Cortex with 2 layers of narrow thick-walled cells followed by 2–3 layers of wider, thinner-walled cells (in total, 4–5 layers, 52 µm length; Fig. 8C ). Vascular bundles in 8–9 alternating cycles ( Fig. 8A ). Peripheral, transitional, and central vascular bundles surrounded by a lignified sclerenchyma sheath defining their contour ( Figs. 8D–F ). Cell wall of fiber sheath weakly lignified. Oval central vascular bundles, 462 × 362 μm; two round shaped metaxylem vessels, 89 × 92 μm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 82 × 104 µm; sieve tubes 18 × 21 µm ( Fig. 8F ). Scarce amorphous silica bodies embedded along the periphery of vascular bundles occupying cellular spaces covering a mean area of 187 µm 2 ( Fig. 8B ). Sporadic conical silica bodies across the ground tissue occupying intercellular spaces covering a mean area of 6 µm 2 .