Taxonomic notes on Cyperus (Cyperaceae: Cypereae) from northeastern Brazil Author Matzenauer, William 0000-0002-3451-4611 wmatzenauer @ gmail. com; https: // orcid. org / 0000 - 0002 - 3451 - 4611 wmatzenauer@gmail.com Author Pereira-Silva, Luciana 0000-0003-0455-8215 silvapeluciana @ gmail. com; https: // orcid. org / 0000 - 0003 - 0455 - 8215 silvapeluciana@gmail.com Author Hefler, Sonia M. 0000-0001-7985-3177 soniahefler @ furg. br; https: // orcid. org / 0000 - 0001 - 7985 - 3177 soniahefler@furg.br Author Alves, Marccus 0000-0001-9281-2257 Departamento de Botânica, Universidade Federal de Pernambuco, 50670 - 901, Recife, Pernambuco, Brazil. & alves. marccus @ gmail. com; https: // orcid. org / 0000 - 0001 - 9281 - 2257 alves.marccus@gmail.com text Phytotaxa 2022 2022-12-22 576 3 297 300 http://dx.doi.org/10.11646/phytotaxa.576.3.6 journal article 54550 10.11646/phytotaxa.576.3.6 c4f58cd3-9da9-44ed-8216-8ddf1c2a3119 1179-3163 7471643 Cyperus ligularis Linnaeus (1759: 867) . Type:— JAMAICA . P. Browne s.n. ( lectotype LINN 70.37! designated by Tucker 1983: 49) . Cyperus pernambucensis Steudel (1854: 42 sphalm. “fernambucensis” ). Type :— BRAZIL . Pernambuco , Fradel s.n. ( holotype P00585581!). Syn. nov. Figs. 1 A-B. Other synonyms associated to C. ligularis can be consulted at Govaerts et al. (2022) . Some of these names may not fit under the taxonomic identity of the species and need further investigation, which is beyond the scope of this article. Another name attributed to the Cyperus in the Brazilian flora which deserves a careful attention is C. planifolius var. pickelii ( R.Gross ex Ķkenthal 1936: 447). It was also proposed by Ķkenthal based on specimens collected by Dom Bento J. Pickel in the Northeast of Brazil , specifically in the states of Paraíba and Pernambuco. Ķkenthal (1936) only provided a brief description for this species, mentioning the spikelets 1.0 mm wide, most congested compared to the other varieties of the species, and ellipsoid achenes. However, our detailed analysis of the original materials of C. planifolius var. pickelii ( Fig. 1C; 1D ) showed that this morphological variation is not coherent with the taxonomic circumscription accepted for C. planifolius Richard (1792: 106) . Cyperus planifolius is known from the Southwestern United States of America ( California ), South of Mexico , Central America ( Tucker 1994 ) and North of the South America ( Govaerts et al. 2022 ). Ķkenthal (1936) also accepted in addition to C. planifolius var. pickelii six other infraspecific taxa. The typical variety of C. planifolius , which corresponds to its original description, has 4–8 inflorescence bracts, persistent spikelets, glumes deciduous and slightly imbricated. Nevertheless, C. planifolius var. pickelii can be readily segregated from the typical form by having 8–9 inflorescence bracts, deciduous spikelets, and glumes persistent and strongly imbricate.Thus, a nomenclatural update is required since C. planifolius var. pickelii does not fit morphologically in the concept adopted for C. planifolius by Richard (1792) and clearly cannot be supported as a variety of this species. Looking for morphologically similar taxa, one caught our attention. Cyperus potiguar ( Ribeiro et al. 2015: 154 ) was recently described based on materials from the state of Rio Grande do Norte , Brazil . Nowadays, it is known that the species is present in most states of the Brazilian Northeast ( Matzenauer et al. 2020 ). The main diagnostics characteristics proposed for C. potiguar by the authors are the leaf blades chartaceous and glaucous, papillose culm, spikes with 8–67 deciduous spikelets, spikelets with (5–)7–11 persistent glumes, and rachilla internodes with 0.9–1.2 mm long. All these characters can also be found in C. planifolius var. pickelii . Only the achene shape shows some distinctions between samples recognized as both species based on the author’s descriptions. Ķkenthal (1936) described the achene of C. planifolius var. pickelii as ellipsoid and Ribeiro et al . (2015) described the achene of C. potiguar as obovoid to ovoid. However, after analyzing several C. potiguar specimens we found a variation in achene shape where ellipsoid form is clearly an intermediary shape between obovoid to ovoid. Thus, since there is no morphological differentiation to clearly delimit two different species, we propose the recognition of C. planifolius var. pickelii and C. potiguar as a single species. A taxonomic change to species level can be proposed to the variety C. planifolius var. pickelii , however it would be subsequent to the valid publication of C. potiguar . Consequently, assuming the priority principle of publication of ICN ( Turland et al. 2018 ; Prin. III, IV), C. planifolius var. pickelii should be placed as a new heterotypic synonym of C. potiguar , as we formally propose here. We also reinforce the need for a lectotype designation to C. planifolius var. pickelii . The original description was based on syntypes , three different samples collected by B. Pickel (3591, 3779, and 3995), with no specification of herbarium where they were deposited ( Turland et al. 2018 ; Art. 9.6 e 40.2). Since there is no clearly indication of a holotype , it is recommended to assign a lectotype among the original materials cited in the description ( Turland et al. 2018 ; Art. 9.4, 9.11, 9.12). Ķkenthal did not specify the herbarium where the exsiccates he studied were deposited and the botanical collection of Pickel are spread out in many locations as B, IPA, NY, P, S, and among others ( Stafleu & Cowan 1983 ). So , we cannot assert with certainty which herbarium those samples were seen, or even if they were really seen by Ķkenthal at B. The notes made by R. Gross on the exsiccates and mentioned by Ķkenthal (“ R. Gross in sched ”), suggest he probably analyzed Pickel’s samples from R. Gross’s herbarium at B. However , none of those samples were located in B, indicating that they were probably lost in the World War II as a hundred of samples from different families, including Cyperaceae ( Hiepko 1987 ) . We found the syntypes associated to C. planifolius var. pickelii at US and IPA. So , we choose B. Pickel 3779 as lectotype of C. planifolius var. pickelii , which best represents morphologically this taxon, and also because it is the only one of the three syntypes that is preserved in two different herbaria.