Otatea, García-Martínez & Terrazas & Sánchez & Reyes & Ruiz-Sanchez, 2023

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 sp. nov. 2 ( Fig. 16 )

Material examined: — MEXICO. Jalisco: Puerto Vallarta, 100 m upstream of Palo María river , 20°33’4.14”N, 105°15’24.48”W, 50 m, 10 December 2021, E. Ruiz-Sanchez 723 ( IBUG!) .

Culm anatomy description: —Culm solid. Epidermis with a layer of axially elongated lignified cells, 22 µm length, with frequent squared to rectangular silica bodies on top ( Fig. 13B ). Cortex with 3–4 layers of strongly thickerwalled rounded cells, 84 µm length ( Fig. 13B ). Vascular bundles in 9–10 alternating cycles ( Fig. 13A ). Peripheral, transitional, and central vascular bundles surrounded by a sclerenchyma sheath defining their contour ( Figs. 13C–E ). Elliptical central vascular bundles 445 × 315 μm; two round shaped metaxylem vessels, 118 × 105 μm; phloem with sieve tubes and companion cells located between two metaxylem vessels on the upper level, 108 × 104 µm; sieve tubes 16 × 28 µm ( Fig. 13E ). Scarce amorphous silica bodies embedded along the periphery of vascular bundles occupying cellular spaces covering a mean area of 173 µm 2. Sporadic conical silica bodies across the ground tissue occupying intercellular spaces covering a mean area of 26 µm 2.

We here present a key to Mexican Otatea species based on anatomical cross-section characters.

Figures

FIGURE 13. Culm cross section of Otatea victoriae. 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.

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.