Taxonomic, nomenclatural and chorological reports on Carex (Cyperaceae) in the Neotropics

Abstract: We present relevant data about the taxonomy, nomenclature, and chorology of nine species of the genus Carex from the Neotropics. We provide two new records for the South American continent, one of them an introduced species in Argentina and Uruguay (C. divisa), and the other an apparently naturally occurring species in Venezuela (C. buxbaumii), two new records for Central America in Costa Rica (C. setigluma) and Guatemala (C. phalaroides), and five other new records at the national level for Colombia (C. larensis, C. ownbeyi, C. tachirensis), Ecuador (C. haematopus) and Uruguay (C. catharinensis), as well as relevant regional records for two of these species in Venezuela (C. larensis, C. tachirensis). We also provide taxonomic observations on the poorly understood C. tachirensis. Finally, we lectotypify three names (C. larensis, C. niederleiniana and C. phalaroides) and propose the synonymization of C. tucumanensis with the earlier described C. niederleiniana. Citation: Jiménez-Mejías P., Strong M., Gebauer S., Hilpold A., Martín-Bravo S. & Reznicek A. A. 2018: Taxonomic, nomenclatural and chorological reports on Carex (Cyperaceae) in the Neotropics. — Willdenowia 48: 117–124. doi: https://doi.org/10.3372/wi.48.48108 Version of record first published online on 5 April 2018 ahead of inclusion in April 2018 issue.


Introduction
Carex L., with about 2000 species, is one of the largest genera of Angiosperms (e.g. Global Carex Group 2015, 2016. It has a cosmopolitan distribution, with more than two hundred species distributed in the Neotropics (Govaerts & al. 2018+). Despite its relative species richness, further study is still needed in Central and South America. The efforts of Reznicek (1986), Reznicek & González-Elizondo (1995) and Wheeler (1987Wheeler ( , 1990Wheeler ( , 1996Wheeler ( , 2002Wheeler ( , 2009, among many other works) have great-ly clarified the taxonomy of several taxonomic groups in these regions. Yet, other groups remain understudied, as evidenced by a number of recently described new species (Jiménez-Mejías & Escudero 2016;Jiménez-Mejías & Roalson 2016;Poindexter & al. 2017).
This publication is a continuation of the revision work started with a first set of miscellaneous notes published by Jiménez-Mejías & al. (2016a). Here we continue to present new relevant taxonomic, nomenclatural, and chorological information, as a result of studying additional herbarium collections.

Material and methods
Material from the following herbaria was studied: A, BOZ, DUKE, HAL, MICH, MO, NY, SI, UPOS and US (abbreviations according to Thiers 2017+). High-resolution images available on the Internet from the herbaria CORD, F, G, K, LE, LPB and VEN were also carefully examined. Specimens were identified using the specialized taxonomic literature cited under each taxon. The species are presented in alphabetical order. The proposed synonymization is discussed at the end of the manuscript. Accepted names follow the World Checklist of Cypera ceae (Govaerts & al. 2018+). Terminology of the inflorescence prophylls (utricles and cladoprophylls) follows the suggestions in Jiménez-Mejías & al. (2016b). Illustrations -Ball & Reznicek (2002: 407), Jermy & al. (2007: 451).

Results and Discussion
Remarks -First record of this Holarctic, predominantly boreal species for the South American continent, constituting the known absolute southernmost native limit of the species. Carex buxbaumii, C. leptalea Wahlenb., C. limo sa L., C. livida (Wahlenb.) Willd., and C. lurida Wahlenb. display a remarkable trans-Caribbean disjunction, being the five species widely distributed in North America and appearing disjunct in the N Andes (Govaerts & al. 2018+), and also on the Island of Hispaniola in the case of C. lep talea, C. limosa and C. lurida. Such disjunction seems to be related to the bird migration via the American Atlantic flyway (Jiménez-Mejías & al. 2016a).
The coordinates provided in the voucher actually lies on the Colombian side of the border, although still pretty close to Venezuela. Since the coordinates are given as approximates and since we cannot authentically discern whether the mistake is in the coordinates or in the country citation, we cite the country as shown on the specimen label.
There is some confusion regarding the typification of the name Carex buxbaumii Wahlenb. and its relationship with the illegitimate C. polygama Schkuhr (Beschr. Riedgräs. 1: 84. 1801, nom. illeg., non C. polygama J. F. Gmel., Syst. Nat. ed. 13[bis]: 145. 1791). While Moberg & Nilsson (1991) correctly typified C. buxbau mii Wahlenb. on a Wahlenberg's herbarium material, Egorova (1999) considered that C. buxbaumii a replacement name for C. polygama Schkuhr., and thus proposed a new lectotypification through the designation of the type material of C. polygama Schkuhr [Egorova (1999: 389): Denmark, Zealand, in uliginosis Siaellandiae, Jul 1799, M. Vahl s.n. (HAL 0103626!)]. However, the case is not as straight forward as it seems. While Wahlenberg (1803) cited Schkuhr's name in the protologue of C. buxbaumii, he also made reference to a Buxbaum's pre-Linnaean work. Since there is no evidence that Wahlenberg wanted to prioritize one citation over the other, and that he actually created the new name after Buxbaum, C. buxbaumii Wahlenb. cannot simply be treated as a replacement name for C. polygama Schkuhr. Moreover, Schkuhr (1801) does not make any reference in his protologue to Buxbaum's work, rejecting the possibility that this name could also be based on Buxbaum's plant. As a consequence, the earlier Moberg & Nilsson (1991) typification must be considered valid for C. buxbaumii Wahlenb., while Egorova's (1999) typification is in form an effective lectotypification of C. polygama Schkuhr, but without any effect on Wahlenberg's name.

Illustrations -Silveira & Longhi-Wagner (2012: 389).
Remarks -We hereby confirm the expected occurrence of this species in Uruguay, given that it was already known north and south of Uruguay in Brazil (Silveira & Longhi-Wagner, 2012) and Buenos Aires province in Argentina (Jiménez-Mejías & al. 2016a). Herter's (1953) report of Carex fuscula d'Urv. was presumably a misapplication of C. catharinensis, and thus C. fuscula is most likely absent in Uruguay. Illustrations -Jermy & al. (2007: 255). Willdenowia 48 -2018 Remarks -This is the first citation of this presumably introduced species in South America, wherein it was apparently formerly misidentified as Carex praegra cilis W. Boott in Río de la Plata region (Herter 1953;Myndel-Pedersen 1968; in both works named as C. marcida Boott). The Argentinian material unequivocally matches C. divisa after comparison with materials of this species and C. praegracilis. In addition, this voucher also matches C. divisa according to Flora of North America key (Ball & Reznicek 2002). The Uruguayan one, despite being immature, also falls much closer within the variation reported for C. divisa than for C. praegracilis. Another Eurasian Carex species, C. divulsa Stokes, is also reported as introduced in some Argentinian provinces of the Río de la Plata Region (Myndel-Pedersen 1968;Jiménez-Mejías & al. 2016a Remarks -These represent the first records of this recently described species for Ecuador. Two of the new records are placed close to, and both north and south, to Kükenthal's (1909)  Illustrations -Steyermark (1951: 64).

Additional specimens examined -
Remarks -So far cited only from its type locality in the state of Lara in Venezuela, here we formally report its presence in Colombia and also in the Venezuelan state of Mérida.
Carex larensis is a distinct species from N South America and belongs to C. sect. Ceratocystis Dumort. (Steyermark 1951;Global Carex Group 2016). It has brown to chocolate-brown staminate and pistillate glumes and 2 -3(4) mm long, elliptic to obovate, often inflated utricles, with beaks 0.3 -0.7(-1.2) mm long, straight or slightly curved, all ascending-spreading, or the middle and lower ones spreading. Although these characteristics clearly distinguish C. larensis from the S South American C. sagei Phil., C. larensis approaches the N hemisphere C. viridula Michx. in these features. However, the latter has lighter glumes (pale brown, stramineous or hyaline), and the middle utricles of each spike are always spreading. Steyermark (1951) cited two collection numbers as the type material of Carex larensis: "Type in herb. Chi. Nat. Hist. Mus., collected in swampy meadow, between Buenos Aires and Paramo de las Rosas, state of Lara, alt. 2285 -3290 m., February 11, 1944, Julian A. Steyermark 55470; also same locality, 55467". Although the semicolon separating numbers 55470 and 55467 might indicate an intention of designating the first as holotype, we understand that it is not sufficiently clear. Accordingly, we perform a formal lectotype designation on the specimen at F from the first collection.  -Wheeler (2002: 202).

Illustrations
Remarks -This is the first citation of this poorly understood species from the N Andes. Until its recent collection from Tucumán province in Argentina (Jiménez-Mejías & al. 2016a), this species was formerly known only from the type locality in Bolivia (Wheeler 2002 Barros (1947: Tab. 195 Remarks -This same collection was reported earlier by Chater (1994) in Flora mesoamericana as Carex plano stachys Kunze. This is the first record of the species for Central America, representing the northernmost limit of the species, until now only known from South America (Govaerts & al. 2018+).

Illustrations -
The Carex phalaroides group is much in need of revision. The specimen we cite from Guatemala approaches Silveira & Longhi-Wagner's (2012) concept of subsp. moesta (Kunth) Luceño & Alves, with the spikes lanceolate and the stem sides concave.

Carex setigluma
Remarks -This is the first record of the species from Central America. The Costa Rican specimen displays some achenes constricted on two sides, contrasting with the original description of Carex setigluma achenes as constricted at only one side. Otherwise, the specimen is typical of C. setigluma.

Illustrations
Remarks -Carex tachirensis was described by Steyermark (1951) on the basis of small-sized plants bearing inflorescences each consisting of a single terminal androgynous spike. Accordingly, Steyermark assigned C. tachirensis to C. subg. Primocarex Kük. (= C. subg. Psyllophora (Degl.) Peterm.), which is the Carex group that embraces the great majority of unispicate taxa (Kükenthal 1909;Egorova 1999;Ball & Reznicek 2002). He discussed the affinities of C. tachirensis with other Neotropical and North American species of that subgenus and concluded that the relationships of C. tachirensis were unclear. The only material of this species known to date was the type collection.
A study of herbarium materials has revealed the existence of a Carex species from Venezuela and Colombia of uncertain affinities. The relevant material consists mainly of plants with inflorescences each bearing a terminal androgynous spike and one to several lateral pistillate or shortly androgynous lateral spikes. Some stems, however, rarely show a single terminal androgynous spike (e.g. Cleef 6960). These unispicate inflorescences provided a key hint to the identity of these collections, pointing to possible affinities with C. tachirensis. The detailed comparison of the utricles and glumes of these specimens with the utricles from the isotype of C. tachirensis at US (Fig. 1), revealed that the morphology of both materials were similar, with clear affinities in beak shape and venation pattern. Consequently, these materials bearing several-spiked inflorescences were also identified as C. tachirensis.
The classification of these new materials implies a significant widening of the taxonomic understanding of Carex tachirensis. Although the most immediate af-Willdenowia 48 -2018 finities of this taxon are still unclear, the presence of non-unispicate specimens, sheathing bracts, and tubular cladoprophylls points to C. subg. Carex. The utricles of C. tachirensis showed strong morphological affinities with the Central American C. chiapensis F. J. Herm. (Reznicek, 1986), especially regarding the raised nerves and the bidentate beak. The new materials constitute a substantial broadening of the morphological circumscription of C. tachirensis, with specimens having stems c. 60 cm tall, leaves flattish, up to 3 mm wide, and inflorescences with up to 7 spikes, the lowermost bract 25 cm long, and the longest spikes 4 cm long on peduncles up to 10.5 cm long.
Although certainly unusual, a few other species of Carex may sometimes bear one or several spikes in their inflorescences, such as C. exilis Dewey (Reznicek & Ball, 1980), C. malmei Kalela and C. monodynama (Griseb.) G. A. Wheeler (Wheeler, 1990;Gebauer & al., 2015), or C. subantarctica Speg. (Barros, 1969;Wheeler, 1987Wheeler, , 2009. Such variation of the inflorescence might be due, at least in part, to different growing conditions. Indeed, an overall reduction of the morphology is also known from high mountain populations of the C. flava group when compared with specimens inhabiting habitats with milder climatic conditions (Jiménez-Mejías & al. 2012, 2014. The majority of the labels in the studied C. tachi rensis specimens refer to rocky outcrops and other poorly developed soils. Accordingly, the different degree of development of the different plants might be due to differences by growing on deeper versus poor shallow soils.
The specimen records provided here constitutes a considerable expansion of the range of Carex tachi rensis, both north and south along the northernmost branch of the Andes. These localities also constitute the first citations of the species for Colombia, which, however, was expected since the species was described from Venezuela but "near the Colombia-Venezuela boundary" (Steyermark 1951