Carex orothanatica Lois, Acedo, Reznicek & Jim. Mejias 2023, sp. nov.
Creators: name: Lois, Raúl
name: Acedo, Carmen
name: Reznicek, Anton A.
name: Jiménez-Mejías, Pedro
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Cyperaceae
Carex
Carex orothanatica

description: Carex orothanatica Lois, Acedo, Reznicek & Jim.Mejías, sp. nov. (Figs. 2–4)
Diagnosis:— The Costa Rican Carex orothanatica is similar to the Guatemalan endemic C. tojquianensis Standley & Steyermark (1953: 64). Both taxa clearly differ in the morphology of the utricle beak, bifid in C. orothanatica vs. truncate in C. tojquianensis, and by the color of its glumes, purplish-black in C. orothanatica vs. dark brown in C. tojquianensis. This new species is also similar to the much larger Carex cortesii Liebmann (1850: 268), endemic from Mexico. Both species clearly differ by leaf dimension, 30–40 cm × 4–5 mm in C. orothanatica vs often longer than 100 cm long and 7–8 mm wide in C. cortesii, the number of spikes of the inflorescence, lower than 10 in C. orothanatica vs higher than 20 in C. cortesii, wider and longer utricles in C. orothanatica, 3.3–3.5 × 1.8–2.0 mm than in C. cortesii, 2.2–2.5 × 1.1–1.3 mm.
Type:— COSTA RICA: Province of Cartago: Cordillera de Talamanca: Cerro de la Muerte, Pan-American Highway, 5 km above Villa Mills (about 8 km above Nivel) 9°34’N 83°45’W, crevices in rock ledges and on Paramo, 3400–3500 m, 25 July 1949, R. W. Holm & H. H. Iltis 563 (Holotype: A! (Figs. 2–4); isotype: P!).
Cespitose, rhizomes densely covered with short yellowish to stramineous hairs. Stems 25–40 cm tall, ± 0.15 mm wide at the middle, smooth, trigonous, sides concave below the inflorescence, reddish-brown at the base. Leaves with welldeveloped blades, largest ones 30–40 cm × 4–5 mm, usually shorter than the stems, linear, subcoriaceous, reddishbrown at the base, W-folded, margin slightly revolute; ligule 0.3–0.4 mm long, acute, orangey-brownish; sheaths orangey-brownish. Inflorescence racemose, 5.0–7.0 cm long, with 7–9 androgynous spikes, spreading or dropping; lowermost bract 5.5–7.5 cm × 2–3 mm, slightly longer than the inflorescence, subcoriaceous, W-folded, sheathless or with a short sheath <3 mm. Spikes 2–3 cm × 5–6 mm, linear to oblong, densely flowered, the distal 1/4 staminate, unbranched, with about 120– 150 female flowers, peduncles smooth, mostly equal or longer than the spikes. Female glumes 3.8–4.0 × 1.6–1.7 mm, ovate to suborbicular, purplish-black with a light green middle longitudinal strip, excurrent into a 0.4–0.5 mm awn, hyaline margins extremely narrow or absent, when present it is along the entire glume length. Stigmas 3, brownish. Utricles 3.3–3.5 × 1.8–2.0 mm, suborbicular, glabrous, brownish-red, smooth, nerveless, contracted at the apex into a 0.3–0.4 mm long beak, smooth, bifid, with the teeth slightly divergent, the sinus between teeth as deep as the whole beak length. Achenes 1.6–1.8 × 0.9–1.1 mm, ovate to elliptic, trigonous, cuneate to round at the base; style strongly lignified, leaving a long cylindrical, 0.2 mm long remnant at the apex of the achene.
Habitat and distribution: —Known only from two collections and one recent iNaturalist observation that confirms the presence of the species (https://www.inaturalist.org/observations/111517173) at Cerro de la Muerte, on the western slopes of Cordillera de Talamanca, growing at an altitude of 3400–3500 m in páramo vegetation.
Phenology:— Flowers and fruits were collected at the end of July.
Etymology: —The epithet “ orothanatica ” is formed by the ancient Greek “ oros ”, mountain, and “ thanatica ”, in reference to “ Thanatos ”, the Death. It refers to the toponym of “Cerro de la Muerte”, which means Mountain of Death, where the type material was collected.
Paratype:— COSTA RICA: Province of San José: Direct line from Hotel La Georgina to Cerro Frío of the Cerro Buenavista complex (Cerro de la Muerte), area with television and radio towers, 9°33’- 34’ N 83 °43’- 46’W, rocky, grassy slope, 3100–3400 m, 20 September 1983, G. Davidse 25041 (MICH!).
description: Published as part of Lois, Raúl, Acedo, Carmen, Reznicek, Anton A. & Jiménez-Mejías, Pedro, 2023, Three newly described species of Carex sect. Fecundae (Cyperaceae) from Central America and typification of two related names, pp. 71-86 in Phytotaxa 579 (2) on pages 73-75, DOI: 10.11646/phytotaxa.579.2.1, http://zenodo.org/record/7543084