Carex huancabambica Gonz. Gallego & Jim. Mejías, 2025

González-Gallego, Luis, Benítez-Benítez, Carmen, Reznicek, Anton A., Cano, Asunción, Oleas, Nora H., Martín-Bravo, Santiago & Jiménez-Mejías, Pedro, 2025, Carex huancabambica (Cyperaceae), a new species from the Peruvian and Ecuadorian Andes, PhytoKeys 265, pp. 161-180 : 161-180

Carex huancabambica Gonz. Gallego & Jim. Mejías sp. nov.

Figs 3 , 5 A – J

Diagnosis.

This species is superficially similar to C. boliviensis , from which it primarily differs by stiff short stems (wiry and flexuous in C. boliviensis ), as well as by the utricle shape, broadly elliptical (ovate to narrowly elliptical in C. boliviensis ). From the also closely-related C. angustispica , C. huancabambica differs in its smaller size, with culms from <0.50 (subacaulescent) to 25 cm (( 3 –) 10–65 cm in C. angustispica ) as well as in the shape of the utricles (ovoid to obovoid in C. angustispica ).

Type.

Peru • Piura: Camino a la Laguna Negra, pajonal con matorral , 3,510 m alt., 05°03.9421'S, 79°29.8658'W, 10 Oct 2021, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 73 PERPJM 21 ( holotype: UPOS 18941 !; isotype: USM!) .

Specimens examined ( paratypes).

Ecuador • Azuay: Totorococha – Mazan valley, Área Nacional de Recreación Cajas , paramo grassland, 3,600 m alt., 02°53.00000'S, 79°10.00000'W, 12 Sep 1987, P. M. Ramsay & P. J. Merrow-Smith 529 ( QCA 206613 !, QCNE 122100 !) ; • Carchi: Provincia de Carchi en los cantones Tulcán, Espejo y Mira, Bosque Siempre Verde Montano Alto y Páramo de Frailejones en la zona de amortiguamiento de la Reserva Ecológica El Ángel , 3,625 m alt., 00°40.72676'S, 77°51.83465'W, 8 Oct 2011, V. Yunapanta & S. Chimbolema 167 ( QCA 221878 !) ; • same collection data as for preceding, V. Yunapanta & S. Chimbolema 169 ( QCA 221873 !) ; • Imbabura: Cotocachi Province [current Imbabura Province], slopes of Volcan Cotocachi , paramo grassland, 3,900 m alt., 00°35.00000'S, 78°20.00000'W, 11 Oct 1987, P. M. Ramsay & P. J. Merrow-Smith 815 ( QCA 207075 !) ; • Reserva Ecológica Cotacachi – Cayapas, faldas del Fuya – fuya, lagunas de Mojanda , crece en los pajonales que han sido dedicados a la ganadería, 3,819 m alt., 00°08.00000'S, 78°17.00000'W, 24 Oct 2000, L. Endara A. & M. Nonhebel 384 ( QCA 36608 !) ; • Loja: Cerca de Ramos Urku, carretera Loja – Cuenca , pastizal, 2,900 m alt., 03°40.5102'S, 79°16.0522'W, 28 Jul 2022, A. Morales-Alonso, P. Jiménez-Mejías, I. Masa-Iranzo, E. Sánchez 21 ECU-AMA 22 ( UPOS 18944 !, HUTI!) ; • Pichincha: Páramo de Mojanda. Between Laguna Grande and Laguna Negra , in dry pajonal, 3,700–3,800 m alt., 00°08.0000'S, 78°16.0000'W, 30 Jun 1985, S. Lægaard 54586 ( QCA 36437 !); Peru • Cajamarca: Carretera entre Chota y Cutervo, claros encharcados, 3,009 m alt., 06°27.10686'S, 78°45.48876'W, 7 Oct 2021, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 36 PERPJM 21 ( UPOS 18950 !, USM!) ; • same collection data as for preceding, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 37 PERPJM 21 ( UPOS 18942 !, USM!) .

Morphological description.

Plants cespitose (Fig. 3 ). Fertile culms yellowish – green, glabrous, < 0.50–25 cm long, but length variable within the same plant, erect, stiff, not flexuous, sometimes subacaulescent, with the culm concealed by the leaves, stems trigonous, sparsely antrorsely scabrid, especially at the distal part. Basal sheaths not fibrous, purplish-tinged. Leaves with sheaths membranous at top, hyaline, truncate to U-shaped, sparsely pilose, the open margins ciliate; ligule U-shaped, less than 0.5 mm to 1 mm, shorter than wide; blades up to 11 cm long, 2–4 mm wide, flat to M-shaped in cross-section, herbaceous, glabrous to more or less pubescent on abaxial surface, especially proximally and along the margins and veins, margins sparsely antrorsely scabrid, mainly distally. Inflorescences racemose, with (1 –) 3–4 spikes (Fig. 5 A, F ), 14–32 mm long, 4–12 mm wide; proximal bracts leaf-like, 10–40 mm long, 9–21 mm wide, sparsely antrorsely scabrid, glabrous or ciliate on the abaxial face along margins and veins, sheathless or with a sheath up to 2–4 mm long, ciliate at the insertion with the stem; lateral spikes unisexual, pistillate (rarely staminate, seemingly androgynous in some undeveloped lateral spikes); peduncle sparsely antrorsely scabrid to glabrous; terminal spike gynaecandrous, 10.0– 15.5 mm long, 3–4 mm wide, approx. 20–40 pistillate flowers per spike. Pistillate scales (glumes) 1.7–2.5 mm long, 1.0– 1.5 mm wide, elliptical, glabrous, with apex obtuse or acute, sometimes nearly acuminate, rarely with shorter cilia at the apex, brownish distally and yellowing proximally, mid-vein lighter, margins hyaline (Fig. 5 B, G ). Utricles 2.0– 2.8 mm long, 1.0– 1.4 mm wide, broadly elliptical to elliptical – obovate, narrowly biconvex, uniformly brownish-green, glabrous (Fig. 5 H, I ) or loosely pilose on all its surface (Fig. 5 C, D ), with 2 prominent lateral nerves and sides nerveless or nearly so, tapering to the base and to the apex, beakless or with a very short inconspicuous truncate beak. Style withering; stigmas 3. Achenes trigonous, 1.5–1.9 mm long, 0.9–1.3 mm wide, broadly elliptical to suborbicular, almost filling entirely the utricles, tipped by a very short mucronate style remnant (Fig. 5 E, J ).

Distribution and habitat.

(Fig. 1 ) Ecuador (Provinces of Azuay, Carchi, Imbabura, Loja, Pichincha) and northern Peru (Departments of Cajamarca and Piura) in the context of the Amotape – Huancabamba Zone, separating the Northern from Central Andes. Present in open moist habitats on volcanic soils, at 2,900 –3,900 m alt. Given the small size of the plant, additional populations of this species could exist and have been overlooked.

Phenology.

June – October.

Iconography.

Figs 3 , 5 A – J .

Conservation status.

This species is currently known from seven populations, covering a distribution range within an extent of occurrence ( EOO) of 60,219 km 2 and an area of occupancy ( AOO) of 36 km 2 (based on IUCN default cell width of 2 km 2 and estimated according to the proximity of the closest populations studied). This geographic range suggests the application of criterion B 2 for the Endangered category (EN; threshold of < 500 km 2 for AOO; IUCN (2024)). While the number of locations (<10) would indicate the potential application of the Vulnerable ( VU) category under criterion B 2, the lack of data on the demographic tendency of the studied populations and the fact that probable additional overlooked populations of this species exists, prevent the application of any threatened categories, as no more than one sub-condition can be fulfilled (at least two are needed). Based on the available data from the studied material (Suppl. material 2) and considering the restricted AOO, we hypothesise that C. huancabambica should be currently classified as Data Deficient ( DD) according to the global IUCN conservation categories. Therefore, at present, there is not sufficient information to conduct a complete assessment of the conservation status of this species.

Etymology.

The species epithet, huancabambica , is derived from the Huancabamba Depression within the Amotape – Huancabamba Zone in the Andes, that extends between Piura and Cajamarca in northern Peru to Loja in southern Ecuador.

Systematic and biogeographic notes.

The description of this new species highlights the taxonomic complexity within Carex sect. Porocystis , especially among its understudied Neotropical taxa. The phylogenetic analyses (Fig. 2 ) reveal that C. angustispica is among the closest related taxa to C. huancabambica , despite its exclusive occurrence in the Mexican States of Oaxaca and Querétaro and its absence from South America ( Reznicek and González-Elizondo 2001). Additional phylogenetic resolution is still needed to understand the placement of C. angustispica within sect. Porocystis. Carex boliviensis appears to be the sister taxon to the C. angustispica - C. huancabambica clade and inhabits similar mountain environments as C. huancabambica , but south of the Amotape – Huancabamba Zone, through the Central and the north of the Southern Andes, reaching higher altitudes (up to 4,100 m). No shared localities have been recorded between C. boliviensis subsp. boliviensis and C. huancabambica , the latter only being recorded immediately north of the distribution limit of C. boliviensis subsp. boliviensis in South America. Only a single locality in Oaxaca, southwest Mexico, is known to harbour more than one species of sect. Porocystis ( C. angustispica and C. boliviensis subsp. boliviensis ; Reznicek and González-Elizondo (2001)).

Figures

Figure 1. Distribution map representing the Neotropical species of Carex sect. Porocystis. Occurrence data (Suppl. material 2; Sanz-Arnal et al. 2025 a, b) includes the studied specimens of Carex huancabambica sp. nov. (field collections and herbaria specimens examined, deposited at HUTI, QCA, QCNE, UPOS and USM).

Figure 2. Bayesian phylogenetic tree obtained from the concatenation of nrDNA (ITS and ETS) and cpDNA (matK) sequences of species of the Castanea Clade including one tip per taxon and multiple tips per taxon for the focal populations, highlighted in grey. Both BI posterior probabilities (PP> 0.8) and ML bootstrap (BS> 60 %) values are given above and below branches, respectively, for bold thick branches. The placement of Carex huancabambica sp. nov. is highlighted in red colour. Tip labels include the geographical origin of the specimen using TDWG level 3 region abbreviations (“ botanical countries ”; Brummitt (2001)) and the ID-specification of the specimen or voucher (Suppl. material 1).

Figure 3. Holotype of Carex huancabambica sp. nov. (P. Jiménez-Mejías et al. 73 PERPJM 21) preserved at Universidad Pablo de Olavide Herbarium (UPOS 18941).

Figure 5. Comparative illustration of the main diagnostic morphological characters of Carex huancabambica (A – J), Carex boliviensis (K – O) and Carex angustispica (P – T). A – J. Details of inflorescence (A, F); glume (B, G); abaxial face of utricle (C, H); adaxial face of utricle (D, I); achene (E, J) of Carex huancabambica (A – E holotype, PERU, P. Jiménez-Mejías et al. 73 PERPJM 21, UPOS 18941; F – J P. Jiménez-Mejías et al. 37 PERPJM 21, UPOS 18942). K – O. Details of inflorescence (K); glume (L); abaxial face of utricle (M); adaxial face of utricle (N); achene (O) of Carex boliviensis (PERU, S. Martín-Bravo et al. 224 SMB 21 bis, UPOS 18943). P – T. Details of inflorescence (P); glume (Q); abaxial face of utricle (R); adaxial face of utricle (S); achene (T) of Carex angustispica (holotype, MEXICO, A. A. Reznicek 8093, MICH 1210074). Scale bars: 4 mm (A, F, K, P); 1 mm (B – E, G – J, L – O, Q – T).