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Bamboos (Bambusoideae, Poaceae) are multiple-purpose perennial grasses, which display a growing production chain in Brazil. One of the main bottlenecks is high-quality supplying of plantlets, then requiring efficient mass propagation methods, such as micropropagation. Contamination by microorganisms is recurrent in bamboo in vitro cultures, although some of those manifestations are considered endophytes harboring plant growth promotion potential. The isolation of endophytic bacteria from in vitro cultures of Dendrocalamus asper and Bambusa oldhamii was performed to assess their potential growth-promoting effect in co-cultivation with in vitro plants of Guadua chacoensis, an economically promising bamboo species. Among the total bacterial collection (32 isolates), all of them showed growth-promotion potential as indole compounds-producers. Sequences of 16S rRNA genes from eight selected isolates were newly generated, and the BLASTn similarity test recovered four bacterial genera (Bacillus, Brevibacillus, Serratia, and Atlantibacter) and six species. The co-cultivation experiment was carried out with three isolates selected based on their low- (Ba16), medium- (Ba03), and high-yield (Ba24) production of indole compounds, and Bayesian inferences strongly supported them as Bacillus subtilis, Serratia marcescens, and Brevibacillus parabrevis, respectively. The co-cultivation with three bacterial isolates, and their dilution levels, did not influence shoot or root growth and, however, did not cause apparent impairment for G. chacoensis in vitro cultures. Taken together, the isolation of endophytic microorganisms from field-growth bamboo clump and its co-cultivation with in vitro cultures of bamboos is possible, encouraging a continuous discovery and improvement of micropropagation techniques.

Although karyotype features are useful data for evolutionary studies, cytogenetic data in Bambusoideae are mainly based only on chromosome counts. The first comparative cytogenetic analysis of three Neotropical woody bamboo species - Guadua chacoensis, G. angustifolia and Chusquea tenella - was undertaken based on new and reviewed chromosome counts, CMA/DAPI double staining, fluorescent in situ hybridization (FISH) with 35S and 5S rDNA probes, and genome size estimation. The two species of Guadua were found to have 2n = 46 chromosomes, while the first record for C. tenella was 2n = 44. Only one pair of CMA+/DAPI- was detected on the terminal region of metacentric chromosomes in all three species. Likewise, one pair of 5S and 35S rDNA sites was detected in all three species, with the 35S rDNA sites always collocated with the CMA+ bands. Genome sizes ranged from 2C ≈ 3.99 pg for the species of Guadua, to 2C = 4.77 pg for C. tenella. Considering the Miocene origin of Neotropical woody bamboos, the observed karyotype stability suggests that the analyzed species are diploidized paleopolyploids. The results reveal the conservative cytomolecular organization of Neotropical woody bamboo karyotypes, which helps to improve our understanding of the evolution of this group.

Bamboo plantation has gained great attention in Brazil due to its useful production provided to the society and the ecological, economic, social and cultural functions of these plantations. For the establishment of high productivity plantations, evaluation of germplasm and selection of superior genotypes is necessary. This work aimed at early evaluation of the genetic parameters of potential bamboo species for planting in Brasília/DF. For this purpose, a clonal test consisting of seven species was established: Bambusa oldhamii, Bambusa vulgaris, Bambusa vulgaris var. vittata, Dendrocalamus asper, Dendrocalamus latiflorus, Guadua angustifolia and Guadua chacoensis. The experiment was planted in a completely randomized block design, with three replications and fifteen plants per plot. At 360 days after planting, all individuals were evaluated for their characteristics: height of aerial part, number of sprouts, clump base area, clump coverage area and density of stalks per clump. The statistical analyses were carried out through the procedure of mixed models: Maximum Residual Likelihood/Better Non-Victimised Linear Prediction. There were significant species effects on the characteristics of the aerial part height and number of shoots, as well as high estimates of selective accuracies. Genetic parameters and genotypic values demonstrate genetic variability between species and the possibility of future gains from selection. New evaluations will be carried out annually to aim a greater knowledge of the behavior of germplasms at different ages. At the age of five (commercial court), the best genotypes will be selected for the experimental environmental conditions.

The aim of this study was to develop simple sequence repeat (SSR) markers for genetic studies on G. chacoensis, as well as to evaluate their transferability to other bamboo species. Genomic DNA was isolated from G. chacoensis and its partial sequencing was used to find SSR loci. The obtained sequencing data were de novo assembled using the software CLC Genomics Workbench(®) 8.0v. The SSR loci primers were identified and designed with the software SSRLocator. The selected markers were validated using 56 plants sampled in seven populations from southern Brazil. The markers with potential polymorphism were selected and fluorescently labeled for characterization by capillary electrophoresis. In total, 92 SSR loci were found in G. chacoensis contigs. Suitable primers were designed for 70 SSR loci, and the remaining 22 SSR loci did not have sequences for primer development. Out of 35 selected SSR markers, after PCR optimization, 10 with high polymorphism potential were characterized. These loci can be used in genetic analyses of G. chacoensis and all of them were successfully transferred to other bamboo species. Non-polymorphic loci require further tests with additional plants, from different populations, to identify possibilities of their use. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-020-02268-4) contains supplementary material, which is available to authorized users.

Background: The present study combines morphological and anatomical studies, cell wall chemical composition analysis, as well as assessment of the nutritional value of Guadua chacoensis foliage leaves.; Results: Foliage leaves of G. chacoensis are a promising source of forage because: (a) as a native woody bamboo, it is adapted to and helps maintain environmental conditions in America; (b) leaf anatomical studies exhibit discontinuous sclerenchyma, scarcely developed, while pilose indumentum, silica cells, prickles and hooks are also scarce; (c) it has a high protein content, similar to that of Medicago sativa, while other nutritional parameters are similar to those of common forages; and (d) glucuronoarabinoxylan, the major extracted polysaccharide, has one-third of the 4-linked β-d-xylopyranosyl units of the backbone substituted mainly with α-l-arabinofuranose as single stubs or non-reducing end of short chains, but also 5-linked α-l-arabinofuranose units, terminal β-d-xylopyranose and d-galactopyranose units, as well as α-d-glucuronic acid residues and small amounts of its 4-O-methylated derivative.; Conclusion: These results constitute the first report on this species, and as culms are utilized in constructions and crafts, the remaining leaves, when used as forage, constitute a byproduct that allows an additional income opportunity. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

Fusoid cells have been interpreted as cells or intercellular spaces, according to different authors. Here, structural and ultrastructural evidence is provided relative to the origin and changes experimented by chlorenchyma cells (“arm cells”) to differentiate into fusoid cells with large intercellular spaces between them. Performed studies and observations were made using Light and Transmission Electron Microscopy. Fusoid cells in Guadua species die but do not remain intact; instead, they uniformly collapse, delimiting conspicuous intercellular spaces which are bigger and different in shape from these cells. In transverse sections of mature and expanded bamboo leaf blades, usually seen in anatomical descriptions, the socalled “fusoid cells” are actually conspicuous intercellular gas spaces delimited by successive collapsed (and rarely not collapsed) fusoid cells. Also, we hypothesize possible relations or links between fusoid cell shape, structural function and apoplastic transport in bamboo leaves. Fil: Vega, Andrea Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; Argentina Fil: Castro, María A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina Fil: Guerreiro, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Guadua chacoensis (Poaceae) is a woody bamboo native from the Atlantic forest biome. Morphogenetic and physiological studies are scarce in bamboos, and tissue culture-based biotechnologies tools can be used to investigate ultrastructure and physiological processes as well as to mass-propagate specific genotypes. This study evaluated the effect of light and dark conditions on chloroplast biogenesis as well as in the endogenous levels of zeatin (Z), abscisic acid (ABA), gibberellic acid (GA4), and jasmonic acid (JA) during in vitro culture of G. chacoensis. An increase was observed, followed by a decrease in starch content in response to light treatment, and in contrast, in darkness, an accumulation of starch which is associated to amyloplast formation at day 30 was observed. No etioplast formation was observed even in the dark and this was associated with the presence of fully developed chloroplast at the beginning of the experiment. Z levels quantified showed distinct behavior, as in light, no difference in the levels was observed, except at day 10, and in darkness, the levels increased along the evaluation time. ABA, GA4, and JA biosynthesis increased along the time of evaluation in light condition. In contrast, in darkness, the levels remained unaltered, excepted for an increase in JA levels at day 10, suggesting a strong relationship between light and these phytohormone levels. Possible reasons why light’s presence and absence cause changes in chloroplast ultrastructure and hormone endogenous levels in in vitro cultivated culms of G. chacoensis are discussed. Keywords Bamboos · Micropropagation · Transmission electron microscopy · Plant physiology · Phytohormone Made available in DSpace on 2019-03-02T00:37:13Z (GMT). No. of bitstreams: 1 Polesi2019ArticleChloroplastUltrastructureAndHo.pdf: 1356355 bytes, checksum: 25b47e78e8251e1ff16794227f651cc5 (MD5) Previous issue date: 2019-01-10

The bamboo productive chain is still incipient in Brazil, and the low supply of plantlets due to low-efficient conventional propagation methods presents a significant bottleneck to its development. This study aimed to establish a micropropagation protocol for Guadua chacoensis. Explants from donor plants cultivated under controlled environment showed less contamination, if compared to explants from plants grown in the field. The contamination rate was even lower when 2 mL L-1 of Plant Preservative Mixture (PPMTM) were added to the culture medium, leading to a higher establishment rate. The obtained cultures were then multiplied using either in vitro-derived nodal segments or clump division in the presence of increasing contents (0 µM, 10 µM, 20 µM, 30 µM or 40 µM) of 6-Benzylaminopurine (BAP). The number of shoots increased with increasing BAP concentrations, but this also resulted in a reduced rooting rate and root length. Plants acclimatized under 0 %, 35 % or 65 % of shading showed a dynamic maximum quantum yield of photosystem II (Fv/Fm), which initially decreased within the first seven days after the transfer to ex vitro conditions, but then increased until reaching stable values of 0.775 after 17 days. Additionally, the shading improved the plant survival rates, if compared to those under non-shaded conditions, which presented photoinhibition and photodamage symptoms. KEYWORDS: Bamboo in vitro establishment, micropropagation protocol, chlorophyll fluorescence.

Fil: Alchouron, Jacinta. Universidad de Buenos Aires. Facultad de Agronomia. Catedra de Botanica General; Argentina

BACKGROUND: The present study combines morphological and anatomical studies, cell wall chemical composition analysis, as well as assessment of the nutritional value of Guadua chacoensis foliage leaves. RESULTS: Foliage leaves of G. chacoensis are a promising source of forage because: (a) as a native woody bamboo, it is adapted to and helps maintain environmental conditions in America; (b) leaf anatomical studies exhibit discontinuous sclerenchyma, scarcely developed, while pilose indumentum, silica cells, prickles and hooks are also scarce; (c) it has a high protein content, similar to that of Medicago sativa, while other nutritional parameters are similar to those of common forages; and (d) glucuronoarabinoxylan, the major extracted polysaccharide, has one-third of the 4-linked β-d-xylopyranosyl units of the backbone substituted mainly with α-l-arabinofuranose as single stubs or non-reducing end of short chains, but also 5-linked α-l-arabinofuranose units, terminal β-d-xylopyranose and d-galactopyranose units, as well as α-d-glucuronic acid residues and small amounts of its 4-O-methylated derivative. CONCLUSION: These results constitute the first report on this species, and as culms are utilized in constructions and crafts, the remaining leaves, when used as forage, constitute a byproduct that allows an additional income opportunity. © 2016 Society of Chemical Industry. Fil: Panizzo, Cecilia C.. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente; Argentina Fil: Fernández, Paula Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina Fil: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina Fil: Ciancia, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina Fil: Vega, Andrea Susana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente; Argentina

Stilobezzia enigma, a new Neotropical species, is described and illustrated from larvae, pupae and adults. Larvae and pupae were collected from internodes of two bamboo species, Guadua chacoensis (Rojas) and Guadua trinii (Ness) Ness ex Rupr (Bambuseae) in Misiones province, Argentina, and were examined in the laboratory with a scanning electron microscope. The generic placement of S. enigma is somewhat uncertain but we provide cladistic evidence indicating that it is probably an autapomorphic member of Stilobezzia. Fil: Ronderos, Maria Marcela. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Spinelli, Gustavo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Borkent, Art. No especifica

The complete plastome sequencing is an efficient option for increasing phylogenetic resolution and evolutionary studies, as well as may greatly facilitate the use of plastid DNA markers in plant population genetic studies. Merostachys and Guadua stand out as the most common and the highest potential utilization bamboos indigenous of Brazil. Here, we sequenced the complete plastome sequences of the Brazilian Guadua chacoensis and Merostachys sp. to perform full plastome phylogeny and characterize the occurrence, type, and distribution of SRRs using 20 Bambuseae species. The determined plastome sequence of Merostachys sp. and G. chacoensis is 136,334 and 135,403 bp in size, respectively, with an identical gene content and typical quadripartite structure consisting of a pair of IRs separated by the LSC and SSC regions. The Maximum Likelihood and Bayesian Inference analyses produced phylogenomic trees identical in topology. These trees supported monophyly of Paleotropical and Neotropical Bamboos clades. The Neotropical bamboos segregated into three well-supported lineages, Chusqueinae, Guaduinae, and Arthrostylidiinae, with the last two forming a well-supported sister relationship. Paleotropical bamboos segregated into two well-supported lineages, Hickeliinae and Bambusinae + Melocanninae. We identified 141.8 cpSSR in Bambuseae plastomes and an inferior value (38.15) for plastome coding sequences. Among them, we identified 16 polymorphic SSR loci, with number of alleles varying from 3 to 10. These 16 polymorphic cpSSR loci in Bambuseae plastome can be assessed for the intraspecific level of polymorphism, leading to innovative highly sensitive phylogeographic and population genetics studies for this tribe.

Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cyclic pattern of gregarious flowering after long vegetative periods. The flowering cycle has been described in very few species. The goal was to identify mass flowering events of woody bamboo species native to Argentina and neighboring areas, and to estimate the flowering cycle of each species. Sixteen species were surveyed: Chusquea culeou, C. deficiens, C. lorentziana, C. montana, C. quila, C. ramosissima, C. tenella, C. valdiviensis; Colanthelia rhizantha; Guadua chacoensis, G. paraguayana, G. trinii; Merostachys clausenii, M. multiramea, Rhipidocladum neumannii and R. racemiflorum. To reconstruct flowering dates, information from literature and herbarium collections was consulted and more than 990 records were gathered. Flowering cycles were estimated by recording the intervals between reported flowering events. Evidence of regular flowering cycles of ca. 30 years was found for most of the species considered. There is a remarkable concentration of flowering cycles about multiples of 15–16 years. Flowering synchrony among different species of woody bamboos was recorded for the first time in South America. Fil: Guerreiro, Carolina Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

This Master thesis has been performed at CTD- the Centre for Wood Technology and Design at the University of Linköping and has been carried out in Santa Cruz de la Sierra in Bolivia. The objective of this thesis is to study the mechanical properties and uses of Guadua chacoensis, a bamboo native to Bolivia. Throughout history, bamboo has been used in many countries for a variety of purposes. In Asia bamboo is an important raw-material for buildings and furniture. It is also used for making paper and for land rehabilitation and fuel. In South America many countries, among them Bolivia, have great potential to use bamboo in the same way. One of the key ideas with this Master thesis is to make a contribution to support the Bolivian economy and welfare by elucidate this, hitherto undeveloped, natural resource. This thesis is a Minor field study partly financed by Sida- the Swedish International Development Cooperation Agency. During the field study theoretical studies were made, collecting local and international information about bamboo and Guadua chacoensis in particular. Laboratory tests were prepared and conducted at UPSA- the Private University of Santa Cruz de la Sierra and several localities of the plant were visited. Through tensile-, bending- and hardness test it is found that Guadua chacoensis is a flexible, medium soft material and is comparable with European oak when it comes to the tensile strength. This leads to the conclusion that this bamboo species, among other fields of applications, can be used for constructions, like houses and bridges, and furniture manufacturing. Diese Diplomarbeit wurde durch das CTD- Zentrum für Holztechnik und Design an der Universität Linköping betreut und in Santa Cruz de la Sierra in Bolivien durchgeführt. Das Ziel dieser Arbeit ist es die mechanische Beanspruchung und die Anwendungen von Guadua chacoensis , einer bolivischen Bambusart, zu untersuchen. Bambus wurde in der Vergangenheit in vielen Ländern für die unterschiedlichsten Anwendungen wie zum Beispiel Häuser, Werkzeug, Möbel, Lebensmittel, Treibstoff und Papier verwendet. In meisten asiatischen Ländern ist Bambus ein wichtiger Rohstoff für kleine und mittlere Unternehmen. Damit werden Arbeitsplätze geschaffen, was der Bevölkerung hilft die Armutsgrenze zu überwinden. Auch in Lateinamerika haben viele Länder, wie zum Beispiel Bolivien, die Chance Bambus in der gleichen Weise zu nutzen. Ein zentraler Gedanke dieser Arbeit ist es daher eine Grundlage für die bolivische Wirtschaft zu schaffen damit dieser bislang kaum entwickelte Rohstoff genutzt werden kann. Diese Arbeit wurde von Sida- der Schwedischen Internationalen Entwicklungsorganisation, teilweise finanziell unterstützt. Im Rahmen der durchgeführten Studie wurden sowohl theoretische Aspekte betrachtet, als auch Versuche im Labor der privaten Universität von Santa Cruz de la Sierra durchgeführt. Des Weiteren wurden verschiedene Arten des Bambus in der Natur untersucht. Biege- Streck- und Festigkeitsversuche haben gezeigt, dass Guadua chacoensis ein flexibles und weiches Material ist. Von den Streckeigenschaften ist es mit europäischer Eiche zu vergleichen. Diese Ergebnisse führen zu der Schlussfolgerung, dass Guadua chacoensis für die Konstruktion von Häusern und Brücken, für die Herstellung von Möbeln und andere ähnliche Anwendungen eingesetzt werden kann. Esta tesis ha sido realizada en el Centro de Ciencia de Madera y Diseño- CTD de la Universidad de Linköping y ha sido llevada a cabo en la ciudad de Santa Cruz de la Sierra, Bolivia. El objetivo de la tesis es estudiar los propiedades mecánicas y usos de la Guadua chacoensis, un bambú nativo de Bolivia. A lo largo de la historia, el bambú ha sido utilizado en muchas localidades del mundo en distintas aplicaciones, vale mencionar: viviendas, herramientas, muebles, alimentos, combustible, papel y para rehabilitación de la tierra. En casi todos los países Asiáticos el bambú es un recurso importante para empresas de tamaño pequeño y mediano, proporcionando empleo y contrarrestando la pobreza. En América Latina muchos países, incluyendo Bolivia, tienen potencial para aprovechar el bambú del mismo modo. Una de las ideas más importantes de la tesis es hacer una contribución para apoyar a la economía de Bolivia, la cual, hasta ahora, ha desarrollado muy poco este recurso natural. La tesis es un Minor field study parcialmente financiado por Asdi- la Agencia Sueca de Cooperación Internacional para el Desarrollo. Durante el Minor field study estudios teóricos fueron realizados, acumulando información nacional e internacional sobre bambú y Guadua chacoensis en particular. Para examinar los propiedades mecánicos de la Guadua chacoensis, pruebas de laboratorio fueron preparadas y efectuadas en la Universidad Privada de Santa Cruz de la Sierra. Asimismo, muchas áreas con bosques naturales donde crece la especie fueron visitadas. A través de pruebas de laboratorio de tracción, flexión y dureza ha sido demostrado que la Guadua chacoensis es un material flexible y de dureza media, comparable con el roble europeo cuando se trata de la fuerza de tracción. Eso tiene como resultado que la Guadua chacoensis, entre otros campos de aplicación, puede ser usada para construcciones, como casas y puentes, y para la manufacturación de muebles. Detta examensarbetete har gjorts vid CTD- Centrum för Träteknik och Design vid Linköpings universitet och har utförts i Santa Cruz de la Sierra i Bolivia. Syftet med detta examensarbete är att studera de mekaniska egenskaperna och användningsområden för Guadua chacoensis, en boliviansk bambuart. Genom historien har bambu använts i en mängd olika applikationer såsom hus, verktyg, möbler, mat, bränsle, papper och land-rehabilitering. I de flesta asiatiska länder är bambu en viktig resurs för små- och medelstora företag vilket skapar arbetstillfällen och motverkar fattigdom. I Sydamerika finns många länder, däribland Bolivia, vilka har stora möjligheter att utnyttja bambu på samma sätt. En av huvudidéerna med detta examensarbete är att kunna gynna den bolivianska välfärden genom att belysa denna, hittills outvecklade naturresurs. Detta examensarbete är en Minor field study, delvis finansierad av Sida, styrelsen för internationellt utvecklingssamarbete. Under fältarbetet genomfördes teoretiska studier då internationell och inhemsk information om bambu, speciellt om Guadua chacoensis, samlades in. Olika områden där arten växer besöktes och hållfasthetstekniska tester genomfördes vid UPSA- Universidad Privada de Santa Cruz de la Sierra. Genom drag-, böj- och hårdhetsprovning har det påvisats att Guadua chacoensis är ett böjligt och medelhårt material med en draghållfasthet som är jämförbar med den för Europeisk ek. Detta gör att denna bambuart lämpar sig bland annat för konstruktioner, såsom hus och broar, samt möbeltillverkning.

Guadua angustifolia Kunth is the largest and most economically important bamboo in the Western Hemisphere. It is the primary source of building material for urban and rural dwellings in many areas within its geographical range, especially in Colombia and Ecuador. Guadua aculeata Rupr. ex Fourn. from Central America and Bambusa (Guadua) chacoensis N. Rojas from Argentina and Paraguay are two closely related taxa that were often confused with or identified as G. angustifolia. These three taxa comprise the Guadua angustifolia complex

A new combination, Guadua chacoensis, is made. Based on morphological evidence, G. chacoensis appears closely allied to G. trinii. A detailed illustration of the species is included, and morphological descriptions and illustrations of the seedling and fruit are provided. Guadua was segregated from the genus Bambusa Schreber and described by Kunth (1822). Important diagnostic characters that distinguish this genus are triangular culm leaves in which the margins of the sheath and blade are usually contiguous, a distinctive band of short white hairs above and below the nodal line, synflorescences with 2to many-flowered pseudospikelets, a palea of firm texture with prominent wings emanating from the keels, and the presence of stomata and papillae on the adaxial surface of the leaf blades (Soderstrom & Ellis, 1987; Soderstrom & Londofio, 1987). Other characters useful in distinguishing among the species of the genus are the shape of culm and foliage leaf, the structure and shape of pseudospikelets, and the habit of the plant. Guadua occurs throughout tropical America, from Mexico to northern Argentina, and contains perhaps 30 species. Along with Guadua, four other genera are placed in the subtribe Guaduinae: Criciuma Soderstrom & Londoiio and Eremocaulon Soderstrom & Londoiio from Brazil, and Olmeca Soderstrom and Otatea (McClure & Smith) Calder6n & Soderstrom, from Mexico (Soderstrom & Ellis, 1987). Guadua chacoensis occurs in northern Argentina, southeastern Bolivia, and southern Paraguay and is one of the three southeasternmost species of the genus. It is frequently misidentified as G. angustifolia Kunth. The species was described in 1918 by the Argentinian botanist Nicolas Rojas Acosta as Bambusa chacoensis. A type specimen was not designated but the locality data (General Vedia, Depto. Bermejo, Prov. del Chaco-Argentina, and Ile de la Colonia Aquino, Rio Paraguay) and the common name "tacuara," distinguish it from two species that occur sympatrically, G. paraguayana Doell, "picanilla," and Guadua trinii (Nees) Ruprecht, "yatevo," "tacuaruzu," or "tacuara brava" (Nicora & Ruigolo, 1987; Young, 1985). McClure (1973), in his annotated checklist of species, included G. chacoensis under the heading of unresolved specific taxa. Young (1985) treated this species as one of two subspecies in the variable Guadua angustifolia Kunth complex and indicated a neotype. However, Young (1985) pointed out that "the two subspecies can be separated using a combination of vegetative and reproductive characters but since the morphological gap separating them is smaller than that separating most species in the subgenus, the taxa are considered here to be only subspecifically distinct." In this study, a comparison of floral and vegetative morphology among G. chacoensis, G. angustifolia, and G. trinii is presented. Based on complete material collected by Camilo Quarin, a botanist from the Universidad Nacional del Nordeste, Corrientes, Argentina, a detailed illustration of the habit of G. chacoensis and descriptions and illustrations of the seedling and fruit are provided. Guadua chacoensis (Rojas) Londofio & Peterson, comb. nov. Basionym: Bambusa chacoensis Rojas, Bull. Acad. Int. Geogr. Bot. 26: 157. 1918. TYPE: Argentina. Chaco: Departamento Bermejo, General Vedia, Riberas del Rio de Oro, 23 July 1974, Quarin et al. 2384 (neotype, designated here, CTES; isoneotypes, F, G not seen, MO, US). Figure 1. Woody, thorny bamboo. Rhizomes pachymorph. Culms 10-20 m tall, 8-15 cm diam., green, erect below and arching apically; internodes hollow; nodes solitary; bud solitary, covered by a prophyll, positioned 2-4 mm above the nodal line. Culm leaves NOVON 2: 41-47. 1992. This content downloaded from 157.55.39.163 on Sat, 19 Nov 2016 04:22:52 UTC All use subject to http://about.jstor.org/terms