Otatea ximenae, Ruiz-Sanchez & Clark

García-Martínez, Miguel A., Terrazas, Teresa, Sánchez, Daniel, Reyes, Pablo Carrillo- & Ruiz-Sanchez, Eduardo, 2023, Culm anatomy of the genus Otatea (Poaceae, Bambusoideae, Bambuseae, Guaduinae) as a contribution to Mexican species identification, Phytotaxa 609 (2), pp. 75-102 : 93

Otatea ximenae ( Fig. 14 )

Material examined: — MEXICO. Oaxaca: Asunción Nochixtlán, Km 190 of the Puebla-Oaxaca highway, 17°23’9.1”N, 97°8’8.9”W 1928 m, 2 February 2020, Ruiz-Sanchez & M . A . García-Martínez 645 ( IBUG!) .

Culm anatomy description: —Culm solid. Epidermis with a layer of axially elongated lignified cells, 12 µm length, with occasional rectangular silica bodies on top ( Fig. 16C ). Cortex with one layer of thick-walled cells followed by 2 layers of wider, thinner-walled ovoidal cells (3 layers in total, 30 µm length; Fig. 16C ). Vascular bundles in 5–6 alternating cycles ( Fig. 16A ). Peripheral, transitional, and central vascular bundles surrounded by a sclerenchyma sheath defining their contour ( Figs. 16D–F ). Ovate central vascular bundles, 309 ×304 μm; two round shaped metaxylem vessels, 75 × 83 μm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 78 × 98 µm; sieve tubes 19 × 20 µm ( Fig. 16F ). Ground parenchyma with abundant starch grains. Frequent conical silica bodies across the ground tissue occupying intercellular spaces covering a mean area of 10 µm 2 ( Fig. 16B ).

Figures

FIGURE 14. Culm cross section of Otatea ximenae. A. Cross section general view. B. Central area with vascular bundles following different orientations. C. Epidermis and hypodermis. 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.

FIGURE 16. Culm cross section of Otatea sp. nov. 2. A. Cross section general view. B. Epidermis and cortex. C. Peripheral vascular bundle. D. Transitional vascular bundle. E. Central vascular bundle. Abbreviations: co, cortex; ep, epidermis; fs, fiber sheath; mx, metaxylem; pa, parenchyma; ph, phloem; px, protoxylem; sc, sclerenchyma; si, silica bodies.