Olmeca chazaroi Ruiz-Sanchez & Marinero-Sobal, sp. nov. Fig. 1–2

TYPE:— MEXICO. Veracruz: Huatusco, cerro de Ixpila, lado más oeste de la cordillera, 19°7’7.59”N, 96°59’13.77”W, 1600 m, 15 Noviembre 2020 (fl), E. Marinero S., D. Canales, A. Seedorf & M. Cházaro 430 (holotype IBUG!, isotypes MEXU!, XAL!).

Olmeca chazaroi differs from O. clarkiae by having 3–4 branches per node (vs. 1-branch), longer oral setae on culm leaves (20–45 mm vs. 8–15 mm long), foliage leaf sheaths glabrous (vs. prominently papillose-hirsute), narrower foliage leaf blades (3.5–6 mm vs. 9–15 mm wide), spikelets with 3–4 florets (vs. 2-flowered), and lemmas pubescent (vs. glabrous).

Rhizomes pachymorph 10–15 cm long and sympodial. Culms 3–8 m tall, 5–15 mm in basal diameter, erect to scandent culms; internodes 31–42 cm long, terete, asperous and retrorsely bearded, green, hollow, the walls 1–3 mm thick, the lacuna occupying>50% of the total diameter. Culm leaves 15.5–23 cm long, not-overlapping, persistent; sheaths 7.2–14 cm long, the sheaths are 1.3–1.9 times longer than the blades, persistent, triangular, abaxially hispid along the entire sheath, the hairs dark brown 1.2–1.4 mm long, auricles absent, the margins ciliate at the upper third; inner ligule ca. 0.1 mm; oral setae 20–45 mm long, 0.1–0.2 mm wide, yellowish, flattened, scabrous; fimbriae 3–12 mm long, ca. 0.1 mm wide, terete, whitish, deciduous, straight or curly, glabrous; blades 7–9.8 cm long, narrowly triangular, erect or reflexed, adaxially and abaxially glabrous, the margins glabrous. Branching intravaginal; 3–4 branches per node, diverging from each other, the main branch 276–310 cm long, 5–7 mm wide diverging from the main culm at 45–75 o, secondary branches 2–3 mm wide; supranodal ridge pronounced; nodal line horizontal. Foliage leaves (9–)10–12(–15) per complement; sheaths glabrous, auricles absent; margins glabrous; outer ligule an irregular glabrous rim 0.1–0.2 mm long; inner ligule 0.2–0.5 mm long, truncate; oral setae 5–15 mm long, 0.1–0.2 mm wide, yellowish, flattened, glabrous, fused with the inner ligule; fimbriae on shoulder at one side of the blade at the sheath apex, ca. 5 mm long, terete, glabrous, straight, free; pseudopetioles hardly differentiated; blades (13–) 18.5–25 cm long, 3.5–6 mm wide, linear, adaxially and abaxially glabrous, green on both sides, the base attenuate, folding, the apex acute, midrib excentric, visible for the full length; the margins entire with short teeth. Synflorescences paniculate, 5–7 cm long, terminal on leafless branches, with 8–15 spikelets, the rachis angular, scabrous; pedicels 2-5 mm long, angular, scabrous. Spikelets 17–21 mm long, with 3–4 florets, sometimes the uppermost floret sterile; rachilla joints 3.2–4 mm long, scabrous. Glumes 2, unequal, narrowly triangular and navicular, shortly awned, abaxially scabrous; glume I 3–3.8 mm long including the awn, 3-nerved, the awn 0.4–1 mm long; glume II 4.2–5 mm long including the awn, 7-nerved, the awn 1–1.5 mm long; lemmas 9–11 mm long including the awn, narrowly triangular and navicular, abaxially pubescent, 9-nerved, the awn 3–4 mm long, antrorsely scabrous; paleas 6–6.8 mm long, the keels scabrous, the sulcus pubescent, the wing glabrous to scabrous at the apex, the apex entire and pubescent. Lodicules 3, abaxially glabrous, hyaline, ciliate, the anterior pair 1.2–1.4 mm long, the posterior one 1.2 mm long, cilia hyaline, 0.05–0.09 mm long; anthers not seen; ovary not seen. Caryopsis not seen.

Etymology: —The specific epithet commemorates Miguel Cházaro Basáñez (August 15, 1949 - April 4, 2023), our esteemed colleague and the collector of this species, in recognition of his contributions to Mexican botany.

Phenology: —Flowers of this species were collected in 2020 and 2024, with only a single individual flowering each year. This suggests a sporadic flowering pattern (Franklin 2024).

Distribution and habitat: —This narrowly endemic species is restricted to Cerro de Ixpila (Huatusco, Veracruz), where it occurs in a single montane cloud forest population at 1600 m elevation (Rzedowski 1978) (Fig. 3).

Notes: ―The 2024 collection yielded one post-flowering individual with a single spikelet on a secondary branchlet. Its glumes, lemmas, and paleas measured twice the size of those in the 2020 specimen. We excluded the 2024 measurements due to this apparent anomaly. A formal IUCN analysis of conservation status could not be performed due to the lack of sufficient data points. Its provisional status would be Critically Endangered.

Uses: —Local people from Huatusco made baskets with this species.

Paratypes: ― MEXICO. Veracruz: Huatusco, cerro de Ixpila, lado más oeste de la cordillera, 19°7’7.59”N, 96°59’13.77”W, 1600 m, 9 Agosto 2024, E. Ruiz et al. 866 (IBUG).