TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida Taxonomic re-evaluation of Panicum sections Tuerckheimiana and Valida (Poaceae: Panicoideae) using morphological and molecular data Mabel A. Lizarazu, Marcela V. Nicola & Diego L. Salariato Instituto de Botánica Darwinion, Labardén 200, Casilla de Correo 22, B1642HYD, San Isidro, Buenos Aires, Argentina Author for correspondence: Mabel A. Lizarazu, mlizarazu@darwin.edu.ar DOI http://dx.doi.org/10.12705/632.34 Abstract The taxonomic status of Panicum sect. Tuerckheimiana and sect. Valida has remained as “incertae sedis” within Panicum. To resolve the systematic position of both sections within Paniceae s.l., morphological studies and phylogenetic analyses based on chloroplast sequence data (ndhF) were conducted. Our study shows that both sections are included in the subtribe Paspalinae of tribe Paspaleae, where they are related with the genus Anthaenantiopsis. These results support the recent transfer of these species to the recently described genera Aakia and Osvaldoa; they are restricted to forests of Mesoamerica and lowlands of southern South America respectively. These genera are described and compared with other allied genera of subtribe Paspalinae. Keywords Aakia; Anthaenantiopsis; ndhF phylogeny; Osvaldoa; Paniceae; Panicum; Paspaleae; Paspalinae; Tuerckheimiana; Valida Supplementary Material The alignment is available at TreeBASE, http://www.treebase.org/, study accession no. S14182. INTRODUCTION Panicum L. has traditionally been considered as one of the largest genera of Poaceae with nearly 450 species worldwide distributed mainly in tropical and subtropical regions (Webster, 1988). The taxonomy of the genus has always been controversial, mainly due to the great amount of variability of morphological, anatomical, and physiological characters (Ellis, 1988; Crins, 1991). During the 19th century, the traditional broad concept of Panicum and related genera was challenged by Chase (1906, 1908a, b, 1911) for the New World species, and Stapf (1920) for Old World species (especially Africa); they pointed out the need of excluding outlying species from the genus. Hitchcock & Chase (1910) recognized two subgenera and 13 informal groups for Panicum species of North America. Pilger (1931, 1940), Hsu (1965), and Brown (1977), using morphological, anatomical, and physiological characters, divided Panicum in different groups, sections, and subgenera. Later, Zuloaga (1987) proposed a classification for the New World species of Panicum, based on exomorphological, anatomical, and karyological characters, in which he recognized 6 subgenera and 25 sections. Several phylogenetic studies of Panicoideae based on chloroplast (ndhF, trnL-F, rpoC2) and ribosomal nuclear (ETS) sequence data, as well as morphology corroborated the polyphyly of Panicum (Gómez-Martínez & Culham, 2000; Zuloaga & al., 2000; Duvall & al., 2001, 2003; Giussani & al., 2001; Aliscioni & al., 2003). Aliscioni & al. (2003), in a phylogenetic analysis based on ndhF gene sequences, restricted Panicum to those taxa usually placed in Panicum subg. Panicum, and characterized it by including caespitose plants, with ciliate or membranaceousciliate ligules, spikelets arranged in open and lax inflorescences, with the upper glume and lower lemma (5–)7–13-nerved, the upper anthecium indurated, and the palea with simple or compound papillae toward the apex. Species of Panicum s.str. are C4, of the NAD-me subtype, and have a basic chromosome number of x = 9. Consequently, Aliscioni & al. (2003) transfered species to other panicoid genera (such as Dichanthelium (Hitchc. & Chase) Gould, Hymenachne P.Beauv., and Steinchisma Raf.), and recognised Phanopyrum (Raf.) Nash as an independent genus. Aliscioni & al. (2003) also suggested that all “incertae sedis” species of Panicum should be segregated from the genus and transfered to new taxa or to extant genera. As a result, many species were transferred recently to other panicoid genera, i.e., Apochloa Zuloaga & Morrone (Sede & al., 2008), Canastra Morrone & al. (Zuloaga & al., 2006), Cyphonanthus Zuloaga & Morrone (Morrone & al., 2007), Hopia Zuloaga & Morrone (Zuloaga & al., 2007), Ocellochloa Zuloaga & Morrone (Sede & al., 2009), Parodiophyllochloa Zuloaga & Morrone (Morrone & al., 2008), Renvoizea Zuloaga & Morrone (Sede & al., 2008), and Stephostachys Zuloaga & Morrone (Zuloaga & al., 2010). Among the “incertae sedis” taxa that were still remaining in Panicum, there are two monospecific Kranz sections: sect. Tuerckheimiana (Hitchc.) Zuloaga, with P. tuerckheimii Hack., a species restricted to humid forests of southern Mexico, Belize, Guatemala, and Nicaragua; and sect. Valida Zuloaga & Morrone with P. validum Mez, a species growing in borders of rivers and streams in southern Brazil, Uruguay, and Received: 2 May 2013 | returned for revision: 12 Nov 2013 | revision received: 7 Jan 2014 | accepted: 23 Jan 2014 | published online ahead of inclusion in print and online issues: 3 Apr 2014 || © International Association for Plant Taxonomy (IAPT) 2014 Version of Record (identical to print version). 265 TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida Argentina. Recently, Grande Allende (2014) proposed the establishment of the new genera Aakia J.R.Grande and Osvaldoa J.R.Grande for P. tuerckheimii and P. validum, respectively. The paper by Grande Allende is solely based on previously published literature and does not contain any new analyses. In consequence, the aim of this study is to evaluate the taxonomic position of sect. Tuerckheimiana and sect. Valida using a morphological analysis of the taxa and a chloroplast (ndhF) DNA phylogeny of Paniceae s.l. MATERIALS AND METHODS Morphological data. — Morphological characters were recorded from herbarium specimens from ANSM, BAA, BAB, CHAPA, CTES, F, G, LIL, MEXU, MO, NY, R, SI, SP, and US. Upper anthecia were examined with a JEOL.J.S.M. 25SII Scanning Electron Microscope (SEM) at the Facultad de Odontología of the Universidad de Buenos Aires, Argentina. Molecular data and phylogenetic analyses. — The ndhF gene was amplified and sequenced for two specimens of Panicum validum, one specimem of Panicum tuerckheimii, and one specimen of Anthaenantiopsis fiebrigii Mez (for voucher information and GenBank accession numbers, see Appendix 1). For this purpose total DNA was isolated from herbarium material using a DNeasy plant mini kit (Qiagen, Hilden, Germany). The ndhF gene was amplified in four fragments using primer pairs 5F/536R, 536F/972R, 972F/1666R, and 1666F/3R (Olmstead & Sweere, 1994). Polymerase chain reactions (PCRs) were performed in 25 or 50 µL containing 20–40 ng/µL of DNA template, and a final concentration of 1× PCR buffer without Mg, 5 mM MgCl2, 0.025 mM of each dNTP, 0.2 mM of each primer, and 1.25–3 U Taq polymerase (Invitrogen, Buenos Aires, Argentina). The PCR amplifications were set at 1 cycle of 96°C for 4 min; 39 cycles of 94°C for 1 min 30 s, 55°C for 1 min, and 72°C for 1 min 30 s; and a final extension cycle of 73°C for 7 min. Macrogen (Seoul, Korea) performed cleaning of PCR products using Montage PCR purification kits from Millipore (Billerica, Massachusetts, U.S.A.) following manufacturer’s protocol. Sequencing reactions were also performed by Macrogen using a MJ Research (Watertown, Massachusetts, U.S.A.) PTC-225 Peltier thermal cycler and ABI PRISM BigDyeTM terminator cycle sequencing kits with AmpliTaq DNA polymerase (Applied Biosystems, Foster City, California, U.S.A.), following protocols supplied by the manufacturer. Sequences were assembled and edited using the program Chromas Pro v.1.41 (Technelysium Pty, Brisbane, Queensland, Australia). The ndhF sequences for P. tuerckheimii and P. validum obtained by Aliscioni & al. (2003; AY188494 and AY188495, respectively) were also included in the phylogenetic analyses. The nhdF dataset was deposited in TreeBase (http://www.treebase.org/; study accession number, S14182). Phylogenetic analyses were conducted using a ndhF matrix of 247 taxa extracted from Morrone & al. (2012). This matrix was especially suitable since it presents an extensive sampling of Paniceae s.l. (Paspaleae J.Presl + Paniceae s.str.; GenBank 266 numbers are given in Appendix 1). Sequence alignments were generated with Muscle v.3.6 (Edgar, 2004) using the default settings. Alignment was improved by visual refinement using the program BioEdit v.7.0.9.0 (Hall, 1999) preserving the reading frame. The ndhF dataset was analyzed using maximum parsimony (MP), maximum likelihood (ML), and Bayesian inference (BI) approaches. In the analyses, gaps were treated as missing data. For MP analyses, tree searches were generated with the program TNT v.1.1 (Goloboff & al., 2008) using heuristic searches with 1000 random addition sequences, tree bisection-reconnection branch swapping (TBR), and holding 10 trees per replicate; generated trees were then submitted to a new round of TBR branch swapping to completion. Support values for nodes were estimated using Jackknife (JK) analysis (Farris & al., 1996) with 2000 replicates of 10 random-addition sequences, holding four trees per replicate and using the default removal probability (0.36). Maximum likelihood analyses were conducted using RAxML v.7.2.6 (Stamatakis, 2006). The model of nucleotide substitution TVM + I + G was selected with the Akaike information criterion (AIC) implemented in Modeltest v.3.7 (Posada & Crandall, 1998). The algorithm implemented in RAxML was used for carrying out nonparametric bootstrap (BS) analyses (Felsenstein, 1985) and searches for the best-scoring ML tree in one single run (Stamatakis & al., 2008). We executed 1000 rapid bootstrap inferences and thereafter a thorough ML search under the GTRGAMMAI model. Bayesian analyses were conducted in BEAST v.1.7.2 (Drummond & al., 2012), with settings as follows: GTR + I + G substitution model, empirical base frequencies, four gamma categories, uncorrelated rate variation with lognormal distribution, random starting tree, a Yule process as tree prior, auto-optimization option for operator, and default values for all other settings. Two runs of 8 × 106 generations, sampling every 1000th generation, and discarding the first 25% of the samples as burn-in (2000 samples) were used. Additionally, the hypothesis of inclusion of P. tuerckheimii and P. validum in subtribe Panicinae with the remaining species of Panicum s.str. was tested using the Bayes factor (BF; Brown & Lemmon, 2007). The BF approach was based on smoothed estimates of marginal likelihood estimated with Tracer v.1.5 (Rambaut & Drummond, 2007). A difference of lnBF (unconstrained/constrained) > 20, taking into account the standard error, was used to indicate support on the unconstrained topology over the constrained topology (P. tuerckheimii and P. validum included into Panicinae). RESULTS Morphological data. — Panicum tuerckheimii is a caespitose perennial herb with culms erect to ascendant; ligules membranaceous, brown; with collar purplish, shortly pilose to glabrous; blades lanceolate, flat, herbaceous, narrowed and incurved at the base; inflorescences composed of a lax and diffuse panicle with branches divergent from the main axis; spikelets lanceolate, sparsely pilose on the upper glume and lower lemma with appressed hairs; lower glume reduced, nerveless; Version of Record (identical to print version). TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida upper glume 5-nerved; lower lemma glumiform, 5-nerved; lower palea and lower flower absent; upper anthecium oblongoid, pale, shiny, with simple papillae distributed all over the lemma and palea, and with long unicellular macrohairs toward the apex (Fig. 1A). Plants of Panicum validum are caespitose, shortly rhizomatous perennials herbs with culms erect, hard, solid or with a small lumen, many-noded, and elliptic in transverse section; ligules membranaceous; blades linear-lanceolate, the lower leaf blades keeled, hard, with a manifest midnerve, the upper leaf blades flat and herbaceous; inflorescence composed of an oblong and contracted panicle; spikelets long-ellipsoid, glabrous, and with the nerves conspicuous and anastomosing toward the apex; lower glume ovate-lanceolate (1–)3-nerved; upper glume and lower lemma 5(–7)-nerved; lower palea present, elliptic, membranaceous; pistillode occasionally present; upper anthecium ellipsoid, pale, shiny, more or less indurated, papillose all over its surface, with simple papillae regularly distributed, and apex of the lemma and palea with multicellular, fusiform microhairs (Fig. 1B). Molecular data. — The ndhF alignment had a length of 2074 bp, of which 708 were phylogenetically informative (ca. 34%). Sequence alignment was trivial, with five informative indels from 6 to 24 bp long, as already obtained and described by Giussani & al. (2001) and Morrone & al. (2012). The MP analyses recovered more than 10,000 most parsimonious trees, and the ML and BI analyses recovered similar topologies showing the same strongly supported clades. All the phylogenetic analyses recovered P. tuerckheimii and P. validum in subtribe Paspalinae Griseb., included in a well-supported clade with the genera Anthaenantiopsis Mez ex Pilg., Hopia Zuloaga & Morrone, and Paspalum L. (JK = 99%, BS = 100%, PP = 100%; Fig. 2A–B). These two species of Panicum were recovered in a clade with Anthaenantiopsis (JK = 87%, BS = 83%, PP = 99%; Fig. 2B) in which Panicum tuerckheimii appeared sister to the latter genus (JK = 94%, BS = 99%, PP = 100%). However, species of Panicum s.str. appeared in a strongly supported clade with other members of subtribe Panicinae Fr. (JK = 88%, BS = 93%, PP = 100%; Fig. 2C). The Bayes Factor test strongly rejected the inclusion of P. tuerckheimii and P. validum in subtribe Panicinae (lnBF [inclusion unconstrained/inclusion constrained] = 227 ± 0.8). DISCUSSION The phylogenetic analyses conducted here strongly support the inclusion of Panicum tuerckheimii and P. validum in tribe Paspaleae. Panicum validum and P. tuerckheimii are the only remnant, non segregated species of Panicum subg. Agrostoides (sensu Zuloaga, 1987). Both species are C4 of the MS anatomical subtype, i.e., they have a single Kranz mestome sheath around each vascular bundle (Zuloaga, 1987; Zuloaga & al., 1989). In grasses, this anatomical feature is correlated with the physiological NADP-me subtype or malate formers (Hattersley, 1987). This anatomical/physiological subtype is characteristic of most members of tribe Paspaleae, whereas in Panicum s.str. the characteristic anatomical/physiological subtype is the PS/ NAD-me, with a mestome sheath and a Kranz parenchymatous sheath around each vascular bundle (Brown, 1977; Hattersley, 1987; Zuloaga 1987). Additionally, the basic chromosome number for P. validum was reported as x = 10 (Zuloaga & al., 1989), in agreement with the typical basic chromosome number of tribe Paspaleae. On the contrary, the typical basic chromosome number is x = 9 in the Paniceae s.str. (Morrone & al., 2012). Within subtribe Paspalinae, Paspalum species differ from P. tuerckheimii and P. validum by having the former branches of the inflorescences unilateral (vs. branches of the inflorescences radiate in P. tuerckheimii and P. validum), rachis narrowly to broadly foliaceus or membranaceous (vs. rachis triquetrous), and lower glume usually absent (vs. lower glume present). Hopia obtusa is distinguished from P. tuerckheimii and P. validum mainly by being stoloniferous (vs. caespitose), by having biconvex spikelets (vs. spikelets plano-convex), lower glume 4/5–1 the length of the spikelet (vs. 1/5–1/3 in P. tuerckheimii and 3/4 in P. validum), upper glume 7–11-nerved (vs. 5(–7)-nerved), and with spikelets arranged in contracted inflorescences (vs. spikelets disposed in lax and open panicles); also, H. obtusa further differs from P. tuerckheimii by the presence of a lower palea and lower flower (vs. lower palea and lower flower absent in P. tuerckheimii), and from P. validum by its hollow internodes, rounded in transverse section and sheaths not keeled (vs. internodes solid or with a small lumen, elliptic in transverse section, and sheaths keeled in P. validum). Additionally, Hopia is restricted to southwestern U.S.A. and northern and central Mexico while P. tuerckheimii is present in southern Fig. 1. SEM photographs of the upper anthecium. A, Aaika tuerckheimii (Smart 41, SI), apex of upper palea with papillae and macrohairs; B, Osvaldoa valida (Smith & Klein 15722, SI), apex of upper palea with papillae and microhairs. — ma, macrohairs; mi, microhairs; p, papillae. Scale bars, 10 µm. Version of Record (identical to print version). 267 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida TAXON 63 (2) • April 2014: 265–274 Fig. 2. Strict consensus tree of 10,000 most parsimonious trees obtained using the ndhF chloroplast gene. A, complete strict consensus tree, black and white arrows, respectively, indicate positions of Panicum validum and P. tuerckheimii within subtribe Paspalinae; branches in bold are shown in B and C; B, clade of subtribe Paspalinae including Hopia, Paspalum, Anthaenantiopsis, P. validum and P. tuerckheimii; inflorescence and spikelet are shown for the last three taxa; values above/below branches represent parsimony jackknife/maximum likelihood bootstrap values; thick branches indicate > 0.95 Bayesian posterior probability; C, “Panicum s.str. clade”, values above/below branches represent parsimony jackknife/maximum likelihood bootstrap values; thick branches indicate > 0.95 Bayesian posterior probability. 268 Version of Record (identical to print version). TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida Mexico, Guatemala, Belize, and Nicaragua; P. validum is distributed from southern Brazil to Argentina and Uruguay. Anthaenantiopsis has four South American species which inhabit tropical and subtropical open areas. The genus is characterized by including caespitose, shortly rhizomatous perennials with erect culms, blades linear-lanceolate to filiform, inflorescences contracted, spiciform, spikelets ellipsoid, densely papillosepilose, with the lower glume scale-like, 1–3-nerved or nerveless, upper glume and lower lemma subequal, 5–7(–9)-nerved, lower palea and lower flower present, and upper anthecium indurated, with bicellular microhairs and prickle hairs toward the apex of lemma and palea, the lemma with flat margins, not inclosing the apex of the palea (Morrone & al., 1993). Panicum tuerckheimii shares with Anthaenantiopsis species a reduced lower glume, and upper anthecium with simple papillae and long macrohairs toward the apex of lemma and palea. However, P. tuerckheimii differs from the latter genus by having lanceolate blades up to 70 × 3.3 cm, inflorescence lax and diffuse, spikelets lanceolate and sparsely pilose, upper glume and lower lemma 5-nerved, and lower palea and lower flower absent. Also, P. tuerckheimii is restricted to tropical forests of Mesoamerica while all species of Anthaenantiopsis grow in open savannas in South America. On the other hand, P. validum can be distinguished from Anthaenantiopsis species by its hard and solid (or with a small lumen) culms, sheaths and lower blades keeled, spikelets glabrous with the lower glume 3/4 the length of the spikelet, and upper anthecium with multicellular, fusiform microhairs. While morphological and molecular evidence strongly support the exclusion of P. validum and P. tuerckheimii from Panicum, their inclusion in subtribe Paspalinae could be done principally in two ways: either within Anthaenantiopsis or in the new monospecific genera described by Grande Allende (2014; Osvaldoa and Aakia, respectively). The inclusion of these two species in Anthaenantiopsis would lead to expanding the diagnostic features of this genus. For example, P. validum has lower glume 3/4 as long as the spikelet (vs. lower glume scale-like in Anthaenantiopsis), and P. tuerckheimii has a lax and diffuse inflorescence (vs. the contracted inflorescence in Anthaenantiopsis). Anthaenantiopsis is strongly distinguished from other genera of Paniceae by several morphological characters (see above), and the inclusion of P. validum and P. tuerckheimii would blur the morphological circumscription of this genus. Therefore, based on the molecular phylogenies obtained and on anatomical/morphological characters, the expansion of the circumscription of Anthaenantiopsis to include these two species would result in a rather polythetic Anthaenantiopsis, with some of the previous diagnostic characters no longer being diagnostic. In conclusion we prefer to include them in the monospecific genera Osvaldoa and Aakia. TAXONOMIC TREATMENT Key to distinguish Aakia and Osvaldoa from related genera 1. Spikelets arranged in unilateral branches, lower glume absent, ocassionally present ..................... Paspalum 1. 2. 2. 3. 3. 4. 4. Spikelets not arranged in unilateral branches, lower glume present .......................................................... 2 Lower glume reduced, scale-like; spikelets sparsely to densely pilose ................................................. 3 Lower glume 3/4 to 4/5 as long as spikelet; spikelets glabrous ............................................................ 4 Inflorescence an open and lax panicle; spikelets without lower palea and flower; blades lanceolate, up to 3.3 cm wide. Mexico, Belize, Guatemala, and Nicaragua . Aakia Inflorescence a contracted panicle; spikelets with lower palea and flower (lower flower sometimes absent in Osvaldoa); blades filiform or linear-lanceolate, up to 1 cm wide. Argentina, Bolivia, Brazil, and Paraguay ........... .............................................. Anthaenantiopsis Inflorescence contracted; spikelets with upper glume and lower lemma 7–11-nerved; sheaths and blades not keeled; rhizomatous perennials, with short and strong rhizomes producing widely creeping stolons .................. Hopia Inflorescence open; spikelets with upper glume and lower lemma 5(–7)-nerved; sheaths and blades keeled; cespitose, shortly rhizomatous perennials .................. Osvaldoa Aakia J.R.Grande in Phytoneuron 22: 1. 2014 ≡ Panicum [unranked] Tuerckheimiana Hitchc. in Britton, N. Amer. Fl. 17(3): 201, 210. 1915 ≡ Panicum sect. Tuerckheimiana (Hitchc.) Zuloaga in Soderstrom & al. (ed.), Grass Syst. Evol.: 296. 1988 – Type: Aakia tuerckheimii (Hack.) J.R.Grande. Caespitose perennial; culms erect to ascendent, geniculate; internodes compressed, hollow, glabrous; nodes dark, pilose. Sheaths shorter than internodes, herbaceous, keeled, pilose toward the ligular region, otherwise glabrous; ligules membranaceous, brown; collar purplish, shortly pilose to glabrous; blades lanceolate, flat, herbaceous, narrowed and incurved at base, apex acuminate, adaxial surface shortly pilose, more so toward the base, lower margins ciliate, midnerve manifest. Inflorescence a lax and diffuse panicle, with branches divergent from the main axis, spikelets paired and shortly pedicellate; main axis triquetrous, scabrous; pulvini densely pilose; branches triquetrous, scabrous. Spikelets lanceolate, greenish to brownish, dorsiventrally compressed, sparsely pilose with appressed hairs on upper glume and lower lemma, upper glume and lower lemma subequal, acuminate; lower glume reduced, ovate, pale brown, nerveless; upper glume 5-nerved, hyaline; lower lemma glumiform, 5-nerved; lower palea and lower flower absent; upper anthecium oblongoid, pale, shiny, with simple papillae distributed all over the lemma and palea, with long macrohairs toward the apex; lemma 5-nerved, palea 2-nerved. Caryopsis ovoid; hilum punctiform, embryo less than half as long as caryopsis. Distribution and habitat. – Tropical rain forests of Mexico, Guatemala, Belize, and Nicaragua. Aakia tuerckheimii (Hack.) J.R.Grande in Phytoneuron 22: 2. 2014 ≡ Panicum tuerckheimii Hack. in Allg. Bot. Z. Syst. 12: 60. 1906 – Holotype: GUATEMALA. Alta Verapaz, Cubilqüitz, 350 m, 1930, H. von Tuerckheim II 820 (W!; Version of Record (identical to print version). 269 TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida isotypes: GH!, NY!, US Nos. 973890!, 973891! & 81303!). See Fig. 3 for an illustration of A. tuerckheimii. Distribution and habitat. – Tropical rain forests of Mexico, Guatemala, Belize, and Nicaragua, where it is found between 200 and 800 m elevation (Fig. 5). Phenology. – In flower and fruit between July and December. Osvaldoa J.R.Grande in Phytoneuron 22: 5. 2014 ≡ Panicum sect. Valida Zuloaga & Morrone in Syst. Bot. 14: 228. 1989 – Type: Osvaldoa valida (Mez) J.R.Grande. Caespitose, shortly rhizomatous perennials; culms erect, many-noded; internodes hard, solid or with a small lumen, elliptic in transverse section; nodes purplish, thickened, glabrous. Sheaths distichous, open, keeled, pale and glabrous, margins membranaceous; ligules membranaceous, arcuate; collar inconspicuous, glabrous; blades linear-lanceolate, shortly pilose toward the base on adaxial surface, otherwise glabrous, margins scabrous, base rounded, apex attenuate; lower leaf blades keeled, hard, with a manifest midnerve, upper leaf blades flat and herbaceous. Inflorescence an oblong and open panicle; main axis wavy, scabrous; pulvini short-pilose; branches alternate to subopposite, more or less appressed to main axis; axis of branches triquetrous, scabrous and pilose toward the base; spikelets densely disposed in pairs or solitary on both sides of the branches; pedicels short, scabrous to scarcely pilose, triquetrous. Spikelets long-ellipsoid, glabrous, brownish, with upper glume and lower lemma subequal, nerves conspicuous and anastomosing toward the apex; Fig. 3. Aaika tuerckheimii (Hack.) J.R.Grande (H. von Tuerckheim II 1457, SI). A, habit; B, spikelet, ventral view; C, spikelet, dorsal view; D–F, lower glume, dorsal view; G, upper anthecium, dorsal view; H, upper anthecium, ventral view; I, caryopsis, scutellar view; J, caryopsis, hilar view. — Drawn by Vladimiro Dudas. 270 Version of Record (identical to print version). TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida lower glume ovate-lanceolate, (1–)3-nerved, acute, midnerve scabrous; upper glume 5(–7)-nerved; lower lemma glumiform, 5(–7)-nerved; lower palea elliptic, membranaceous, glabrous, brownish, pistillode occasionally present; upper anthecium ellipsoid, pale, shiny, more or less indurated, papillose all over its surface, with simple papillae regularly distributed, apex of lemma and palea with multicellular, fusiform microhairs; lemma 5-nerved; lodicules 2, conduplicate. Caryopsis obovoid; hilum oblong; embryo less than half as long as caryopsis. Distribution and habitat. – Southern Brazil, western Uruguay, and eastern Argentina; borders of rivers and streams. Osvaldoa valida (Mez) J.R.Grande in Phytoneuron 22: 5. 2014 ≡ Panicum validum Mez in Bot. Jahrb. Syst. 56, Beibl. 125: 4. 1921 – Lectotype (designated by Grande Allende in Phytoneuron 2014-22: 5. 2014): ARGENTINA. Entre Ríos; Concepción del Uruguay, Arroyo La China, Sep 1876, P.G. Lorentz 840 (CORD!; isolectotypes: B! BAA1988!, fragment ex B, BAF!, GOET006793!, US!; probable isolectotypes: G!, P!). See Fig. 4 for illustration of O. valida. Note. – It may seem strange that Grande Allende (2014) designated as lectotype the specimen P.G. Lorentz 840 (CORD) as specimen used by Mez to describe Panicum validum would probably be the one housed at B. However, Mez did not cite any herbaria for the three gatherings that he cited in the protologue and all representatives of these gatherings are therefore syntypes (Art. 9.5 of the ICN, final sentence). The specimens Fig. 4. Osvaldoa valida (Mez) J.R. Grande (Zuloaga & Deginani 2493, SI). A, habit; B, ligule, ventral view; C, spikelet, lateral view; D, spikelet, ventral view; E, spikelet, dorsal view; F, lower palea with lodicules; G, upper anthecium, dorsal view; H, upper anthecium, ventral view; I, upper palea; J, upper palea with lodicules, stamens, and stigmas; K, multicellular microhair. — Drawn by Vladimiro Dudas. Version of Record (identical to print version). 271 TAXON 63 (2) • April 2014: 265–274 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida Fig. 5. Distribution of Aaika tuerckheimii (Hack.) J.R.Grande (squares) and Osvaldoa valida (Mez) J.R.Grande (circles). in the herbaria other than CORD, included the one kept at B, are isolectotypes. Distribution and habitat. – Restricted to borders of rivers and streams in southern Brazil, where it is found occasionally, western Uruguay, and eastern Argentina, near sea level (Fig. 5). Phenology. – In flower and fruit between October and February. Chromosome number. – 2n = 20 (Zuloaga & al., 1989). For additional specimens examined of Aaika tuerckheimii and Osvaldoa valida see Appendix 2. ACKNOWLEDGEMENTS Funding of this research was provided by CONICET, grant 11220100100207. We like to express our deep gratitude to F.O. Zuloaga for his help, guidance, and valuable suggestions in this work. We also thank to A.A. Sulekic for the specimens of Anthaenantiopsis. LITERATURE CITED Aliscioni, S.S., Giussani, L.M., Zuloaga, F.O. & Kellogg, E.A. 2003. A molecular phylogeny of Panicum (Poaceae: Paniceae): Tests of monophyly and phylogenetic placement within the Panicoideae. Amer. J. Bot. 90: 796–821. http://dx.doi.org/10.3732/ajb.90.5.796 Brown, J.M. & Lemmon, A. 2007. The importance of data partitions and the utility of Bayes factors in Bayesian phylogenetics. Syst. Biol. 56: 643–655. http://dx.doi.org/10.1080/10635150701546249 Brown, W.V. 1977. 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Pp. 287–306 in: Soderstrom, T.R., Hilu, K.W., Campbell, C.S. & Barkworth, M.E. (eds.), Grass systematics and evolution. Washington, D.C.: Smithsonian Institution Press. Zuloaga, F.O., Morrone O. & Dubcovsky, J. 1989. Exomorphological, anatomical, and cytological studies in Panicum validum (Poaceae: Panicoideae: Paniceae): Its systematic position within the genus. Syst. Bot. 14: 220–230. http://dx.doi.org/10.2307/2418908 Zuloaga, F.O., Morrone, O. & Giussani, L.M. 2000. A cladistic analysis of the Paniceae: A preliminary approach. Pp. 123–135 in: Jacobs, S.W.L. & Everett, J.E. (eds.), Grasses: Systematics and evolution. Collingwood: CSIRO. Zuloaga, F.O., Giussani, L.M. & Morrone, O. 2006. On the taxonomic position of Panicum aristellum (Poaceae: Panicoideae: Paniceae). Syst. Bot. 31: 497–505. http://dx.doi.org/10.1600/036364406778388548 Zuloaga, F.O., Giussani, L.M. & Morrone, O. 2007. Hopia, a new genus segregated from Panicum (Poaceae: Panicoideae: Paniceae). Taxon 56: 145–156. Zuloaga, F.O., Scataglini, M.A. & Morrone, O. 2010. A phylogenetic evaluation of Panicum sects. Agrostoidea, Megista, Prionitia and Tenera (Panicoideae, Poaceae): Two new genera, Stephostachys and Sorengia. Taxon 59: 1535–1546. Appendix 1. Species of Poaceae used for the molecular phylogenetic analyses, voucher specimens from which DNA was extracted for sequencing, and GenBank accession numbers. GenBank numbers of sequences generated for this study are in bold. Acroceras zizanioides (Kunth) Dandy, AY029618. Alexfloydia repens B.K.Simon, JN604672. Alloteropsis semialata (R.Br.) Hitchc. subsp. eckloniana (Nees) Gibbs Russ., EU159708. Altoparadisium chapadense Filg. & al., AY029619. Amphicarpum amphicarpon (Pursh) Nash, JN604673. Ancistrachne uncinulata (R.Br.) S.T.Blake, JN604674. Andropogon gerardii Vitman, AF117391. Anisopogon avenaceus R.Br., AF251447. Anthaenantia lanata (Kunth) Benth, AY029640. Anthaenantiopsis fiebrigii Parodi, Argentina: Salta, La Caldera, El Gallinato, Sulekic 597 (SI), KF982002. Anthaenantiopsis rojasiana Parodi, AY029620. Anthephora elongata De Wild.,, JN604675. Anthephora pubescens Nees,, JN604676. Apluda mutica L., AF117392. Apochloa euprepes (Renvoize) Zuloaga & Morrone, AY029657. Apochloa subtiramulosa (Renvoize & Zuloaga) Zuloaga & Morrone, AY188490. Aristida longiseta Steud., U21966. Arthropogon villosus Nees, AY029622. Arundinella hirta (Thunb.) Tanaka, AF117393. Arundinella nepalensis Trin., AF117394. Arundo donax L., U21998. Arundoclaytonia dissimilis Davidse & R.P.Ellis, AY847121. Austrodanthonia laevis (Vickery) H.P.Linder, AF251460. Axonopus anceps (Mez) Hitchc., AY029623. Axonopus fissifolius (Raddi) Kuhlm., AY029624. Bothriochloa bladhii (Retz.) S.T.Blake, AF117395. Bromuniola gossweileri Stapf & C.E.Hubb., AY847124. Bromus inermis Leyss., BIU71037. Calyptochloa gracillima C.E.Hubb., JN604677. Canastra aristella (Döll) Zuloaga & Morrone, DQ355988. Canastra lanceolata (Filg.) Morrone & al., AY029621. Capillipedium parviflorum (R.Br.) Stapf, AF117396. Cenchrus abyssinicus (Hack.) Morrone, GU561512. Cenchrus americanus (L.) Morrone, F499149. Cenchrus ciliaris L., AY029625. Cenchrus compressus (R.Br.) Morrone, AY029672. Cenchrus flaccidus (Griseb.) Morrone, AF499150. Cenchrus myosuroides Kunth, AF499152. Cenchrus pilosus Kunth, AY623746. Cenchrus setiger Vahl, AF499153. Centotheca lappacea (L.) Desv., AY847122. Centrochloa singularis Swallen, JN604678. Centropodia glauca (Nees) Cope, AF251462. Chaetium bromoides (J.Presl) Benth. ex Hemsl., AY029626. Chaetopoa pilosa Clayton, JN604679. Chamaeraphis hordeacea R.Br., JN604680. Chasmanthium curvifolium (Valdés-Reyna, Morden & S.L.Hatch) Wipff & S.D.Jones, AY847125. Chasmanthium latifolium (Michx.) H.O.Yates, AY029694. Chasmanthium laxum (L.) H.O.Yates, AY847126. Chionachne koenigii (Spreng.) Thwaites, AF117397. Chlorocalymma cryptacanthum Clayton, JN604681. Chrysopogon fulvus (Spreng.) Chiov., AF117398. Cleistachne sorghoides Benth., AF117400. Cleistochloa rigida (S.T.Blake) R.D.Webster, JN604682. Coleataenia anceps (Michx.) Soreng, AY188455. Coleataenia longifolia (Torr.) Soreng, AY188482. Coleataenia petersonii (Hitchc. & Ekman) Soreng, AY188479. Coleataenia prionitis (Nees) Soreng, AY029652. Coleataenia tenera (Beyr. ex Trin.) Soreng, AY188491. Cymbopogon flexuosus (Nees ex Steud.) Will. Watson, AF117404. Cyperochloa hirsuta Lazarides & L.Watson, AY847139. Cyphochlaena madagascariensis Hack., JN604683. Cyphonanthus discrepans (Döll) Zuloaga & Morrone, DQ646392. Cyrtococcum accrescens (Trin.) Stapf, JN604684. Dallwatsonia felliana B.K.Simon, JN604685. Danthonia californica Bol., AF251459. Danthoniopsis dinteri (Pilg.) C.E.Hubb., AY847116. Dichanthelium acuminatum (Sw.) Gould & C.A.Clark, AY188485. Dichanthelium clandestinum (L.) Gould, AY188461. Dichanthelium cumbucanum (Renvoize) Zuloaga, AY188464. Dichanthelium koolauense (H.St. John & Hosaka) C.A.Clark & Gould, AY029627. Dichanthelium sabulorum (Lam.) Gould & C.A.Clark, AY029654. Dichanthium aristatum (Poir.) C.E.Hubb., AF117409. Digitaria ciliaris (Retz.) Koeler, AY029630. Digitaria didactyla Willd., AM849203. Digitaria radicosa (J.Presl) Miq., AY029628. Digitaria setigera Roth, AY029629. Dissochondrus biflorus Kuntze ex Hack., JN604686. Distichlis spicata (L.) Greene, AF251464. Echinochloa colona (L.) Link, AY029631. Echinochloa frumentacea Link, AY029632. Echinolaena inflexa (Poir.) Chase, AY029633. Elionurus muticus (Spreng.) Kuntze, AF117410. Entolasia stricta (R.Br.) Hughes, JN604687. Eragrostis curvula (Schrad.) Nees, U21989. Eriachne pulchella Domin, AY618659. Eriochloa punctata (L.) Desv. ex Ham., AY029634. Gerritea pseudopetiolata Zuloaga, Morrone & Killeen, JN604688. Gynerium sagittatum (Aubl.) P.Beauv., AY847120. Heteropogon contortus (L.) P.Beauv. ex Roem. & Schult., AF117411. Homolepis glutinosa (Sw.) Zuloaga & Soderstr., AY029637. Homolepis isocalycia (G.Mey.) Chase, AY029636. Homopholis belsonii C.E.Hubb., JN604689. Hopia obtusa (Kunth) Zuloaga & Morrone, AY029659. Hylebates cordatus Chippindall, JN604691. Hymenachne donacifolia (Raddi) Chase, AY029635. Hymenachne grumosa (Nees) Zuloaga, AY188468. Hymenachne pernambucensis (Spreng.) Zuloaga, AY188478. Hyparrhenia hirta (L.) Stapf, AF117412. Ichnanthus pallens (Sw.) Munro ex Benth., AY029638. Isachne arundinacea (Sw.) Griseb., AY847119. Isachne leersioides Griseb., JN604692. Ixophorus unisetus (J.Presl) Schltdl., AY623749. Karroochloa purpurea (L.f.) Conert & Türpe, AF251458. Keratochlaena rigidifolia (Filg., Morrone & Zuloaga) Version of Record (identical to print version). 273 Lizarazu & al. • Panicum sections Tuerckheimiana and Valida TAXON 63 (2) • April 2014: 265–274 Appendix 1. Continued. Morrone & Zuloaga, EU805492. Lasiacis sorghoidea (Desv. ex Ham.) Hitchc. & Chase, AY029639. Leucophrys mesocoma (Nees) Rendle, GU594628. Lophatherum gracile Brongn., AY847129. Loudetia simplex (Nees) C.E.Hubb., AY847117. Louisiella fluitans C.E.Hubb. & J.Léonard, JN604693. Megaloprotachne albescens C.E.Hubb., JN604694. Megastachya mucronata (Poir.) P.Beauv., AY847123. Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs, AY029649. Melinis repens (Willd.) Zizka, AY029675. Merxmuellera macowanii (Stapf) Conert, AF251457. Mesosetum chaseae Luces, AY029641. Micraira subulifolia F.Muell., AY622316. Microstegium nudum (Trin.) A.Camus, AF443813. Mnesithea selloana (Hack.) de Koning & Sosef, AF117401. Molinia caerulea (L.) Moench, U21995. Moorochloa eruciformis (Sm.) Veldkamp, AY188452. Neurachne alopecuroidea R.Br., JN604695. Ocellochloa chapadensis (Swallen) Zuloaga & Morrone, AY188486. Ocellochloa piauiensis (Swallen) Zuloaga & Morrone, AY029656. Ocellochloa stolonifera (Poir.) Zuloaga & Morrone, AY188488. Oncorachis ramosa (Zuloaga & Soderstr.) Morrone & Zuloaga, AY029686. Ophiochloa hydrolithica Filg., Davidse & Zuloaga, AY029642. Oplismenopsis najada (Hack. & Arechav.) Parodi, AY188453. Oplismenus hirtellus (L.) P.Beauv., AY029644. Orthoclada laxa (Rich.) P.Beauv., AY847128. Otachyrium versicolor (Döll) Henrard, AY029643. Ottochloa nodosa (Kunth) Dandy, JN604696. Panicum adenophorum K.Schum., AY188454. Panicum antidotale Retz., AY188456. Panicum aquaticum Poir., AY029658. Panicum bergii Arechav., AY188457. Panicum cervicatum Chase, AY188459. Panicum chloroleucum Griseb., AY188460. Panicum claytonii Renvoize, AY188462. Panicum deustum Thunb., GU594631. Panicum dichotomiflorum Michx., AY188466. Panicum elephantipes Nees ex Trin., AY029647. Panicum fauriei Hitchc., AY029650. Panicum hylaeicum Mez, AY188470. Panicum miliaceum L., AY188472. Panicum millegrana Poir., AY029660. Panicum mystasipum Zuloaga & Morrone, AY188474. Panicum nephelophilum Gaudich., AY029645. Panicum olyroides Kunth, AY188475. Panicum pedersenii Zuloaga, AY029646. Panicum pilosum Sw., AY188480. Panicum racemosum (P.Beauv.) Spreng., AY188481. Panicum repens L., AY188467. Panicum rudgei Roem. & Schult., AY029661. Panicum sellowii Nees, AY188484. Panicum stramineum Hitchc. & Chase, AY188489. Panicum trichanthum Nees, AY188492. Panicum tricholaenoides Steud., AY188493. Panicum tuerckheimii Hack., AY188494; Mexico: Chiapas, 6 km al S de Palenque, sobre la carretera Catazaje-Ococingo, Cabrera 12312 (SI), KF982003. Panicum validum Mez, AY188495; Argentina: Entre Ríos: Colon, Morrone s.n. (SI), KF982004; Argentina, Entre Ríos, A 5 km de la ciudad de Colón hacia el sur sobre el río Uruguay, Morrone 5386 (SI), KF982005. Panicum verrucosum Muhl., AY188496. Panicum virgatum L., U21986. Paractaenum novae-hollandiae P.Beauv., JN604697. Paraneurachne muelleri (Hack.) S.T.Blake, Newbey 10800 (MO), JN604698. Paratheria prostrata Griseb., JN604699. Parodiophyllochloa cordovensis (E.Fourn.) Zuloaga & Morrone, AY188463. Parodiophyllochloa missiona (Ekman) Zuloaga & Morrone, AY188473. Parodiophyllochloa ovulifera (Trin.) Zuloaga & Morrone, AY029653. Parodiophyllochloa penicillata (Nees ex Trin.) Zuloaga & Morrone, AY188477. Paspalum arundinellum Mez, AY029663. Paspalum conjugatum P.J.Bergius, AY029669. Paspalum conspersum Schrad., AY029666. Paspalum foliiforme S.Denham, AY029690. Paspalum glaziovii (A.G.Burm.) S.Denham, AY029689. Paspalum haumanii Parodi, AY029664. Paspalum malacophyllum Trin., AY029671. Paspalum paniculatum L., AY029667. Paspalum remotum J.Rémy, AY029668. Paspalum vaginatum Sw., AY029665. Paspalum virgatum L., AY029670. Phacelurus digitatus (Sibth. & Sm.) Griseb., AF117418. Phanopyrum gymnocarpon (Elliott) Nash, AY188469. Pheidochloa gracilis S.T.Blake, JN604700. Phragmites australis (Cav.) Trin. ex Steud., U21997. Plagiantha tenella Renvoize, AY029674. Plagiosetum refractum Benth., EU819409. Poecilostachys oplismenoides (Hack.) Clayton, JN604701. Pohlidium petiolatum Davidse, Soderstr. & R.P.Ellis, AY847130. Pseudechinolaena polystachya (Kunth) Stapf, AY029676. Pseudochaetochloa australiensis Hitchc., JN604702. Pseudoraphis paradoxa (R.Br.) Pilg., EF189892. Reimarochloa acuta (Flüggé) Hitchc., Zuloaga & Morrone 9537 (SI), JN604703. Renvoizea trinii (Kunth) Zuloaga & Morrone, EU107783. Reynaudia filiformis (Spreng. ex Schult.) Kunth,, JN604704. Rupichloa acuminata (Renvoize) D.Salariato & Morrone, AY029692. Sacciolepis indica (L.) Chase, AY029677. Schizachyrium scoparium (Michx.) Nash, AF117420. Scutachne dura (Griseb.) Hitchc. & Chase, GU594616. Setaria barbata (Lam.) Kunth, AF499145. Setaria geminata (Forssk.) Veldkamp, AY029662. Setaria grisebachii E.Fourn., AF499141. Setaria italica (L.) P.Beauv., AF499140. Setaria lachnea (Nees) Kunth, AY029683. Setaria macrostachya Kunth, AY029678. Setaria palmifolia (J.König) Stapf, AY029680. Setaria verticillata (L.) P.Beauv., AF499139. Setaria viridis (L.) P.Beauv., U21976. Setariopsis auriculata (E.Fourn.) Scribn., JN604705. Snowdenia petitiana (A.Rich.) C.E.Hubb., JN604706. Sorghastrum nutans (L.) Nash, AF117421. Spartina pectinata Link, AF251465. Spartochloa scirpoidea (Steud.) C.E.Hubb., AY847140. Spheneria kegelii (Müll. Hal.) Pilg., JN604707. Spinifex sericeus R.Br., EF189895. Sporobolus indicus (L.) R.Br., U21983. Steinchisma decipiens (Nees ex Trin.) W.V.Br., AY188499. Steinchisma hians (Elliott) Nash, AY029685. Steinchisma laxum (Sw.) Zuloaga, AY029655. Steinchisma spathellosum (Döll) Renvoize, AY188500. Stenotaphrum secundatum (Walter) Kuntze, AY029684. Stephostachys mertensii (Roth) Zuloaga & Morrone, AY188471.. Steyermarkochloa angustifolia (Spreng.) Judz., JN604709. Stipagrostis zeyheri (Nees) De Winter, AF251455. Streptostachys asperifolia Desv., AY029687. Tatianyx arnacites (Trin.) Zuloaga & Soderstr., AY029688. Thrasyopsis juerguensii (Hack.) Soderstr. & A.G.Burm., JN604711. Thuarea involuta (G.Forst.) R.Br. ex Sm., GU594624. Thyridolepis mitchelliana (Nees) S.T.Blake, Latz 13500 (MO), JN604710. Thysanolaena maxima (Roxb.) Kuntze, U21984. Trichanthecium cyanescens (Nees ex Trin.) Zuloaga & Morrone, AY188465. Trichanthecium parvifolium (Lam.) Zuloaga & Morrone, AY188476. Trichanthecium wettsteinii (Hack.) Zuloaga & Morrone, Y188497. Tricholaena monachne (Trin.) Stapf & C.E.Hubb., FJ486535. Tripsacum dactyloides (L.) L., AF117433. Triscenia ovina Griseb. JN604712. Tristachya biseriata Stapf, AY847118. Uniola paniculata L., AF251463. Uranthoecium truncatum (Maiden & Betche) Stapf, SJ9599. Urochloa mutica (Forssk.) T.Q.Nguyen, AY029691. Walwhalleya subxerophila (Domin) Wills & J.J.Bruhl, JN604713. Whiteochloa capillipes (Benth.) Lazarides, JN604714. Xerochloa laniflora Benth., JN604715. Yakirra australiensis (Domin) Lazarides & R.D.Webster, JN604716. Yvesia madagascariensis A.Camus, GU594636. Zeugites capillaris (Hitchc.) Swallen, AY847133. Zeugites pittieri Hack., AY632374. Zoysia matrella (L.) Merr., U21975. Zuloagaea bulbosa (Kunth) Bess, AY029648. Zygochloa paradoxa (R.Br.) S.T.Blake, EF189896. Appendix 2. Representative specimens examined: species, country, state, locality, collector, collector number, and herbarium acronym (in parentheses). Aaika tuerckheimii (Hack.) J.R.Grande — BELIZE: Toledo, on rock, in high ridge, riverbank beyond Resemideres, Gentle 6917 (F). — GUATEMALA: Alta Verapaz, Cubilquitz, Von Tuerckheim II-1457 (F, G, MO, SI). Petén, San Luis, en orillando el camino para la cumbre, a km 120, Ortíz 1449 (F, MO); La Cumbre, km 135, bordering Chacte Rivere, in low forest, Contreras 6288 (F, MEXU, MO). — MEXICO: Chiapas, 6 km al S de Palenque, sobre la carretera Catazaje-Ococingo, Cabrera 12312 (SI); 19.2 km from turnoff to ruins on road from Palenque toward Ococingo, then take turnoff to Cascada Misolha, Huft & Cabrera 2431 (MO); a 5 km al S de Campamento COFOLASA el cual está a 24 km al de Crucero Corozal, camino Palenque-Boca Lacantum, Martínez 7853 (MO); El Ocote, orilla perturbada de la selva alta sub-perennifolia, Hernández X. s.n. (MEXU 96395); Mun. Tila, Kokijaz, Ton 4687 (MO); Mun. Ocosingo, a 16 km al NW de Boca Lacantum camino a Palenque, Martínez 14783 (MO); 16 km NW of Tumbo, roadside, 17°09′ N, 91°45′ W, Stevens & Martínez 25890 (MO); Mun. Palenque, tropical rain forest adjacent to small cascading river at Agua Azul, Breedlove & Davidse 55244 (MO); Mun. Palenque, slopes and small streams with tropical rain forest along the ridges 6–12 km south of Palenque on the road to Ocosingo, Breedlove 28825 (MEXU, MO); Mun. Palenque, steep slope with lower montane rain forest near Agua Azul, Breedlove & Davidse 55426 (MO); Mun. Ocosingo, tropical rain forest near Cascada Mizola, 25 km south of Palenque on road to Ocosingo, Breedlove & Davidse 55380 (MO). Oaxaca, Chiltepec, Martínez Calderón 750 (MEXU). Puebla, El Rancho de Cocojapa, on the lower slopes of El Cerro de Cuhuatepetl, Tehuacán, Vera Santos 3706a (CHAPA, NY). Veracruz, Matalarga a orillas del Río Metlac, a 2 km de Fortín, Lot 551 (F), 552 (MEXU); Hidalgotitlán, brecha Cedillo-A. Melgar, Vázquez 1328 (ANSM, MEXU, MO). — NICARAGUA: Región Autónoma del Atlántico Norte, Municipio de Siuna, Reserva Bosawas, en las cercanías de la desembocadura del caño el Macho, Rueda & al. 3831 (MO). Osvaldoa valida (Mez) J.R.Grande — ARGENTINA: Corrientes, Dpto. Monte Caseros, Ruta 127 y Arroyo Curuzú Cuatiá, Schinini & al. 17411 (CTES). Entre Ríos, Dpto. Colón, Colón, Morrone s.n. (SI); A 5 km de la ciudad de Colón hacia el sur sobre el Río Uruguay, Morrone 5386 (SI); Dpto. Uruguay, Isla del Puerto, Meyer 10455 (LIL); Isla Uruguay, Báez 17 (BAB); Concepción del Uruguay, Arroyo La China, Burkart 18013, Irigoyen 344, Nicora 3001 (SI), Zuloaga & Deginani 2493 (BAA, MO, NY, SI, SP, US), Zuloaga & al. 3090 (MO, SI), Bacigalupo & al. 583 (MO). — BRAZIL: Rio Grande do Sul, Barra do Quaraí, Valls & al. 1705 (US). Santa Catarina, Porto União, Smith & Klein 15722 (R, US). — URUGUAY: Paysandú, Isla Queguay, en el río Uruguay, Rosengurtt 3798 (BAA, LIL, SP). 274 Version of Record (identical to print version).