New relevant chorological data on sedges (Cyperaceae) of Peru

We present relevant records of nine species of sedges (Cyperaceae) for Peru. For the genus Carex, we present two new national records (C. haematopus, C. lepida), plus relevant data for another six hitherto poorly known species. We also present the first record of Trichophorum rigidum subsp. ecuadoriense for Peru.


Introduction
The basic taxonomic and biogeographic knowledge of biodiversity is being currently neglected as of relatively minor importance in the shadow of growing big data-based biodiversity research.However, without first comprehensively cataloguing the biodiversity, there would not be any resulting big data.Furthermore, basic biodiversity data constitutes the foundation of many other more applied studies, so its taxonomic quality and accuracy are of paramount importance.
The Neotropics are one of the most diverse regions of the World in terms of flora.It combines a high number of plant endemic species with serious, growing threats to nature conservation; both circumstances are reflected in the presence of seven hotspots of biodiversity (Koenig 2016).However, the cataloguing of Neotropical species is still in progress, and in some plant groups, such as graminoids, is much underdeveloped.Carex L. is one of the most diverse plant genera of the world with more than 2000 species (Roalson et al. 2021), with about 200 species inhabiting the South American continent (Jiménez-Mejías et al. 2018a), of which the majority are endemic.Carex lineages colonised South America in several independent events mostly from the Northern Hemisphere continents (Martín-Bravo et al. 2019), and many Neotropical species have retained ecological preferences for temperate-cold habitats at high latitudes or altitudes (Jiménez-Mejías et al. 2018a).Some species are dominant in habitats such as bofedales (high altitude Andean wetlands) or páramos (high altitude Andean grasslands) so they play a critical ecological role.Yet, a comprehensive monographic work on Neotropical Carex is lacking, and as new fieldwork and taxonomic research progress, new findings are steadily published, such as new species and records (e.g.Jiménez-Mejías & Escudero 2016;Jiménez-Mejías & Roalson 2016;Jiménez-Mejías & Reznicek 2018;Jiménez-Mejías et al. 2016, 2018b, 2020a, b, 2021) or partial taxonomic treatments (Wheeler 2007;Jiménez-Mejías & Dorr 2018;Jiménez-Mejías et al. 2021;Ridley & Jiménez-Mejías 2022), revealing the need for much additional work for a more complete understanding of such an ecologically important group of plants.
Peru is a major diversity hotspot for Neotropical Carex (45 species, 7 of them endemic to the country; Jiménez-Mejías et al. 2018a).Since species are primarily found along the Andes, in the southern and central regions, most species are shared with Bolivia, while in the northern part of the country, the species are shared with Ecuador and Colombia (Govaerts et al. 2022).In addition to high-altitude habitats of the Cordillera, a few species are able to enter the lower and warmer montane forests, either in Amazonian or Pacific slopes.
As a result of an international research collaboration between the Universidad Autónoma de Madrid (UAM, Madrid) and Universidad Pablo de Olavide (UPO, Seville), both in Spain, and the Universidad Nacional Mayor de San Marcos (UNMSM, Lima) in Peru, a fieldwork campaign focusing on sedges took place across the Peruvian Andes in 2021.The fieldtrip stretched over 35 days and over 3400 km from Arequipa and Puno in the South to Piura in the North, resulting in 217 collections and more than 300 herbarium specimens.The present paper compiles the most relevant chorological results of this collecting campaign, that took place within the framework of the research project "Macondo", funded by the Madrid Regional Government. the names accepted in the World Checklist of Cyperaceae (Govaerts et al. 2022).General distribution is also based on Govaerts et al. (2022) and complemented with the pertinent literature cited in each epigraph.The terminology for the inflorescence prophylls (utricles and cladoprophylls) follows the suggestions in Jiménez-Mejías et al. (2016).Infrageneric classification follows Roalson et al. (2021) unless otherwise indicated.

Results and Discussion
Occurrences of the studied species are represented in a topographic map of Peru (Map 1) in which the administrative divisions of the country are also indicated.Boott, Ill. Gen. Carex 4: 131 (1867).Gonzales Tiburcio 25PERPJM21.PIURA.Camino a la Laguna Negra, en pajonal con matorral, 5°03'56.52''S79°29'51.95''W(-5.065701, -79.497763), 3510 m, 10 Oct. 2021, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 72PERPJM21.NOTES.Carex amicta is a northern Andean element, distributed from Venezuela south to northern Peru, where it is known from a single location in Cajamarca (Jiménez-Mejías et al. 2020a).Carex amicta presumably belongs to the Decora-clade of the subgenus Carex, because of the utriculiform cladoprophylls at the base of the second-tolast order branches.However, given its unusual, reduced morphology (other species of the group are much larger), its systematic placement requires molecular confirmation.Carex amicta is also atypical regarding its ecological preferences, as it inhabits high altitude mesic paramos, while the other Neotropical species of the Decora-clade grow in montane forest at lower altitudes.

Carex amicta
We provide two new locations for Cajamarca and a new record for Piura province of this species.The localities of Cajamarca constitute the known southernmost limit of the species.We provide two new regional records of this diminutive plant.Despite the possibility that some of these populations may be mere small growing-forms of Carex enneastachya (Jiménez-Mejías et al. 2020a), we present here C. brehmeri separately as a compromise solution to uncover the existence of such taxonomically problematic species in Peru.Clarke, Bull. Misc. Inform. Kew, Addit. Ser. 8: 70 (1908) (Fig. 1B).We provide five additional records of this species, previously reported from two inexact locations in Cajamarca and Áncash (Jiménez-Mejías et al. 2020a).We provide the first record for Piura province.This is a clear example of an overlooked plant with a wider distribution than believed, that actually forms large populations.2018b).It is apparently closely related to the North American C. pellita Willd., and as such it probably also belongs to the Hirta clade, where the type species of the genus Carex is also placed (C.hirta L.; Roalson et al. 2021).Carex haematopus grows in wet habitats, such as wet meadows and lake shores.

Carex haematopus
These are the first national Peruvian records for this species.These constitute the southernmost known limit for the taxon.Carex laegaardii J.R. Starr, Bot. J. Linn. Soc. 179: 33 (in Global Carex Group 2015) (Fig. 1D).
SPECIMENS EXAMINED.PERU.ANCASH: Pista entre Chavín de Huantar y Catac, en prados húmedos en claros de pajonal, 9°41'12.76''S 77°14'32.96''W (-9.686877, -77.242490)We provide additional locations of this species in Peru.This is another example of an apparently relatively widely distributed plant that has been much overlooked, as reflected in its poor representation in Peruvian herbaria.Boott, Ill. Gen. Carex 4: 211 (1867).Carex lepida has mesic preferences and is found in forest understory, as are the other species of the section.

Carex lepida
We provide the first record in Peru of this poorly collected species.This was expected, since the plant is known from locations in adjacent southern Ecuador (Jiménez-Mejías & Reznicek 2018).

Carex pygmaea
SPECIMENS EXAMINED.PERU.PIURA: Camino a la Laguna Negra, en prados húmedos, 5°03'39.96''S79°29'17.52''W(-5.061101, -79.488200), 3553 m, 10 Oct. 2021, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 81PERPJM21.NOTES.Carex pygmaea is a northern Neotropical element, known from Costa Rica to Peru.This species is placed in the Castanea-clade as part of the sect.Longicaules Reznicek, a group with a primarily Neotropical distribution.In Peru it has been reported from a single location in Huánuco (Salvador et al. 2009), which seems to constitute the southernmost limit of the species.It primarily grows in humid páramo, where it may become very abundant, although its diminutive size means it is probably overlooked.

Carex roalsoniana
We provide two additional locations of this species in Piura province that constitute the southernmost known limit for the species.
SPECIMENS EXAMINED.PERU.PIURA: Camino a la Laguna Negra, en pajonal con matorral 5°03'56.52''S79°09'51.95''W(-5.065701, -79.497763), 3510 m, 10 Oct. 2021, P. Jiménez-Mejías, P. García-Moro & R. M. Gonzales Tiburcio 75PERPJM21.NOTES.Trichophorum rigidum is a Tropical Andean element, which grows in high altitude open habitats, and may become dominant in exposed rocky soils.The subsp.ecuadoriense occurs at the northernmost limit of the taxon, and it was known to date only from Ecuador (Dhooge & Goetghebeur 2007).This subspecies differs primarily from subsp.rigidum by its more slender habit (stems 0.9 -1.2 mm width in subsp.rigidum vs c. 0.5 mm width in subsp.ecuadoriense).Future studies may support its status as a distinct species from T. rigidum.This is the first record of this taxon for Peru and the new southernmost limit for the taxon.This is somewhat expected since some locations of this plant in the Ecuadorian province of Loja were adjacent to the Peruvian border.
topographic map of Peru with the occurrences of the new records studied here (represented with different coloured points).When two or more species were found in the same locality, the point appears filled with different colours (one per species).see legend for the species colours.
Another sect.Phacocystis species endemic from the Tropical Andes, known from Colombia to Bolivia, where it grows in wet meadows, bogs, and lake shores. NOTES.