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The leaf alcoholic extracts of six native Argentine species of Vicia (subg. Vicilla, sect. Australis: V. gramineae, V. macrogramineae, V. epetiolaris, Y. montevidensis, V. nana and V. pampicola) and one adventitious species (subg. Vicia, sect. Vicia: V. sativa subsp. nigra) were studied by bidimentional paper chromatography. Eighty phenolic compounds were found in 107 individuals that were studied. In spite of the high intraspecific variability, observed in all the species, the chromatographic identification was possible because of the presence of specific compounds in each of them. Numerical taxonomy methods were applied to estimate the degree of similarity. The distance and association coeficients used generated congruent phenograms that showed seven main groups which agreed with the seven species that were studied and confirm the exomorphological classification. [ABSTRACT FROM AUTHOR]

Interesting botanical and ecological studies used the multivariate approach to describe underlying patterns in large data sets and to answer questions about the structure of the studied systems at various scales. This work aims to encourage the correct use of the multivariate approach and offers guidelines for the appropriate choice of the analysis techniques according to the objectives of the study and the characteristics of the data. Some appropriate applications of principal components, multidimensional scaling, correspondence analysis, discriminant, and cluster analysis in articles published in scientific journals of these disciplines are showed. We used reduced versions of the data matrices from some of these papers to present the methods of analysis in a simple way. The focus is placed on the correct interpretation of the results and the biological questions that can be answered through multivariate analysis. [ABSTRACT FROM AUTHOR]

This paper analyses the practices related to the consumption and management of plants in the central-western sector of the Santa María valley (Catamarca-Tucumán) during the first and second millennium AD. For this purpose, we worked with macroremains recovered in the occupation floors and with microremains present in ceramic vessels from the archaeological sites Morro del Fraile, El Carmen 1, and El Carmen 2. A total of 546 carpological macroremains corresponding to seven families, Amaranthaceae, Cactaceae, Cucurbitaceae, Fabaceae, Malvaceae, Poaceae and Solanaceae, and 10 microremains from the families Cucurbitaceae and Poaceae, were identified. The similarities between El Carmen 2 enclosure 2 and Morro del Fraile rock shelter suggest that sites occupied since the first millennium AD would have taken advantage of a greater diversity of plants, which in turn show a great diversity of management practices, in relation to sites occupied from the second millennium A.D., as observed in El Carmen 1 enclosures 1 and 13. The similarities between El Carmen 2 enclosure 2 and Morro del Fraile rock shelter would also indicate a diversity of contexts within the second millennium AD, with spaces that show a lower diversity of plants (El Carmen 1 enclosures 1 and 13) and spaces that, during the second millennium AD, exhibit practices that refer to those known for the villages of the first millennium AD (Morro del Fraile rock shelter), such as the consumption of a great diversity of wild, weedy and domesticated plants, with a predominance of Trichocereus and various Amaranthaceae. [ABSTRACT FROM AUTHOR]

The genus Cortaderia (Poaceae) includes 19 South American species, separated into four sections. In this paper the species included in sect. Cortaderia are studied. Cortaderia rudiuscula and C. jubata are two names used with different criteria by diverse authors, which has generated confusion and has led to the frequent determination of herbarium specimens as different species of the section. The original description of C. rudiuscula was written on the basis of four syntypes which belong to more than one species. In this contribution we analyzed type specimens and other herbarium materials assigned to C. rudiuscula, apart from additional plants collected in population samplings for this work, and specimens of the remaining species of the section. A Principal Components Analysis (PCA) was conducted on the basis of characters traditionally used to delimit the species of the section. The analysis showed three morphologic discreet groups that fit to C. araucana, C. selloana and C. speciosa. The lectotype of C. rudiuscula was located among the specimens of C. speciosa, and therefore the synonymy of both species is here proposed. A similar analysis showed that C. jubata represents only a portion of the morphologic variability of C. selloana, and the new combination C. selloana subsp. jubata is proposed. The names C. quila and C. quila var. pygmaeum are reduced to the synonymy of C. speciosa. Cortaderia araucana and C. selloana were originally described as dioecious, and later as gynodioecious. In this paper, populations composed of only pistillate plants (apomyctic) are reported for both species, and, consequently, descriptions are amended to include apomictic populations. A key for the four taxa that are here recognized for the sect. Cortaderia is included, together with descriptions, synonymies and distribution maps. [ABSTRACT FROM AUTHOR]

The "broom" Cytisus striatus is cited for the first time for Argentina. This species coexists with the similar but more widespread "scotch broom", C. scoparius, frequent in disturbed habitats of Patagonia and temperate regions worldwide. So far, eight ruderal seed-producing individuals of C. striatus have been spotted in Patagonia. The morphological resemblance between C. striatus and C. scoparius, and the distance between both populations of C. striatus found in Argentina up to now (31 km) suggest that this species could be abundant in Andean regions of Patagonia. This paper provides a key for the identification of the brooms of Tribe Cytiseae present in Argentina. [ABSTRACT FROM AUTHOR]

Eucalyptus is a genus of trees native in Oceania, with five species previously cited as adventive for the Argentinean Flora. In this paper, spontaneous populations of E. viminalis in Argentina are reported for the first time. Specimens were collected at Sierras de Azul, Tandilia System, province of Buenos Aires, and adjacent plain sectors. A description of the morphology of the species and habitat are presented, together with a map indicating the geographical position of the studied populations in Buenos Aires, and images showing the areal expansion of a population in a hill of the Tandilia System. Complementary, an identification key for naturalized Eucalyptus species inhabiting Argentina is provided. [ABSTRACT FROM AUTHOR]

In this paper we characterized and analyzed microscopically starch grains of eight Zea mays modern landraces from Northwestern Argentina (pisingallo, cristalino colorado, perlita, calchaquí, complejo tropical, dentado amarillo-colorado, chullpi, and capia). We created a reference database of local varieties to explore the diversity in the morphological and metric characters of starch grains at intra and inter-racial levels. The aim of this paper was to search for referential elements that could allow better and more reliable identifications of maize starches in archaeological samples. We used descriptive statistics and multivariate analyses; we applied a statistical treatment to estimate the probability of correct classification of starch grains. Results showed high variability within each landrace and a large superposition between varieties. None of the landraces showed distinctive characteristics that allowed an exclusive discrimination. [ABSTRACT FROM AUTHOR]

The present paper reports 18 taxa of Digitaria in Puerto Rico and the Virgin Islands as a contribution to an ongoing floristic project. Digitaria filiformis var. dolichophylla, D. fragilis, D. sacchariflora, and D. similis constitute new reports. Digitaria ekmanii, D. fuscescens, D. panicea, and Digitaria × umfolozi are excluded taxa. This contribution includes synonymy, iconography, geographic distribution and habitat, vernacular names, specimens examined and a key for the identification of taxa. Digitaria filiformis var. dolichophylla is fully illustrated for the first time. [ABSTRACT FROM AUTHOR]

This paper includes 10 new reports for the genus Digitaria: D. abyssinica, D. aequiglumis var. aequiglumis, D. lanuginosa, D. nuda, and D. venezuelae var. fendleri are reported for the first time in Panama; D. argillacea var. nulliseta and D. fuscescens in Honduras; D. sacchariflora in El Salvador and Guatemala; D. sanguinalis in Costa Rica; and D. similis in El Salvador, Guatemala and Panama. Six of these taxa are new reports from Central America: D. aequiglumis var. aequiglumis, D. argillacea var. nulliseta, D. lanuginosa, D. sacchariflora, D. similis y D. venezuelae var. fendleri. Four species are excluded from Central America. Panicum gavanianum is here synonymized under Digitaria similis, a new report from Peril, and Digitaria clavitricha is synonymized under D. venezuelae var.fendleri. Four species are illustrated for the first time. This paper includes synonymy, iconography, geographical distribution and habitat, vernacular names, specimens examined and observations. A key for the identification of taxa is also provided. [ABSTRACT FROM AUTHOR]

Verbascum is a genus of herbs native from Eurasia and northern Africa, with two species cited as naturalized for the Argentinean Flora (V. virgatum and V. thapsus). In this paper the presence of a natural population of V. blattaria in Argentina is reported for the first time. Specimens were collected in the Sierras de Azul, Tandilia System, Buenos Aires province on December 2017 and April 2018. A description of the morphology of the species and habitat, a map of the collection site and a germination test based on collected seeds are provided. A key to differentiate the three species of Verbascum species that grow in Argentina is provided. [ABSTRACT FROM AUTHOR]

Azorella was partially treated in several regional floristic papers in the last three decades. However, there has been no comprehensive taxonomic synthesis of the genus to date. The purpose of this paper is to repair this lack. This synopsis provides: 1) A new infrageneric classification based on the phenetic affinities among species just established in a previous paper. The genus is divided into four sections: Sect. Azorella --with two series: Ser. Azorella and Ser. Squamulosae (Hauman) Martínez--, Sect. Spinosae nov. sect., Sect. Ciliatae Hauman, and Sect. Cirrhosae Hauman emend. Martínez. 2) Keys for recognition of sections, series, and species. 3) A list of the species, including for each a list of synonyms, references to accessible iconography, and common names. 4) Distribution maps for the sections and individual species. 5) A list of excluded taxa. [ABSTRACT FROM AUTHOR]

A new taxonomic treatment of the genus Tragia from Argentina and neighboring areas is provided. At present 15 taxa are recognized and four of them are recorded for the first time for Argentine. T. sellowiana (Klotzsch ex Baillon) Muell. Arg., T. bahiensis Muell. Arg., T. friesii Pax et K. Hoffman and T. uberabana Muell. Arg. var. discolor Chodat et Hassler. The history and systematic relationships within the genus and with other genera are presented. In this paper a new infrageneric classification is proposed. Three section are accepted for South America: Bia (Klotzsch) Muell. Arg., Leptorhachis (Klotzsch) Muell. Arg. and Tragia. Section Bia is recorded for the first time for Argentina; Section Leptorhachis, wich had been reduced to synonymy is rehabilited in this paper. According to this revision, Section Tragia includes Section Ratiga and Section Leucandra as synonyms. The most important morphological and anatomical features of the accepted taxa are discussed. Morphology of the inflorescence has been analized with the aim of establish its typology. A scanning electron microscopic study of the seed coat structure has been made in order to elucidate differences among the species. The taxonomic treatment includes a description of the genus, keys to the sections, species and varieties. All the taxa are described and illustrated. Data of the geographical distribution as well as a list of the selected herbarium material are given and 9 species and 14 varieties are reduced to synonymy for the first time. [ABSTRACT FROM AUTHOR]

This paper deals with the systematic study of the genera Calycorectes, Hexachlamys, Myrciaria, Paramyrciaria, Plinia and Siphoneugena, which represent the subtribe Eugeniinae Berg, in the Argentine flora The paper also present an enlargement of the area of distribution of Myrciaria tenella (DC.) Berg, which up to now has only been mentioned in the NW of Argentina. Paramyrciaria delicatula (DC.) Kausel is accepted instead of Myrciaria delicatula (DC) Berg, because this species has embryo with two plane-convex cotyledons and a circumcised, elongated hypanthium The new combination Plinta baporeti (Legrand) Rotman, is proposed for a species caracteristic of galleria forests The name Plinia trunciflora (Berg) Kausel has been accepted, in its author's true sense, for a species which up to now has only once been collected in Argentina. Descriptions and illustrations of every species of Hexachlamys, Siphoneugena and Calycorectes are given. Guapurium peruvianum Poir, remains as an entity of doubtful taxonomic position. It has been collected on many an opportunity, but its embryonic morphology is difficult to interprete because it shows polyembryos which, so far, have not allowed correct interpretation of this entity. [ABSTRACT FROM AUTHOR]

The article presents a summary of the 100 years of the Darwiniana magazine, which is dedicated to plant science. The magazine was founded in 1922 by Dr. Cristóbal Hicken and has published 1457 original scientific papers in the field of botany. The quantity and quality of taxonomic revisions of genera are highlighted, as well as the description of around 700 new species of Argentine flora. Throughout the years, the magazine has undergone changes in its sections, authors, and editorial committee, but has maintained its commitment to the quality and importance of local publications. [Extracted from the article]

The vegetal macro-remains recovered at the site Los Conitos (northwestern Mendoza, Argentina) provide evidence of the consumption and management of wild and domestic plant species. Based on these data, the goal of this paper is to improve our understanding of the socio-economic process of gathering and management of plant species during the Late Holocene. The recovery method was dry screening. The chronology is based on eight radiocarbon dates that span the last three thousand years, which are evaluated in conjunction with macro-botanical remains. Of the 207 remains, Prosopis was the most ubiquitous. The excavation levels were grouped into four occupation components. In the oldest, component IV, no vegetal taxa were documented; component III includes the earliest presence of domestic plant remains, squash, and a predominance of wild plant species; component II shows a diversification of the use of plant resources; finally, component I included only wild plants. These data are explored with alternative explanations for the incorporation, replacement, or lasting presence of productive and gathering practices and that may be connected to: abiotic stresses that affect horticultural practices, demographic increase and intensification, and the arrival of migrants with a diversified subsistence base. The principal conclusion allows us to sketch a picture of the implementation of small-scale horticultural systems beginning around 1500 years ago, during which gathering continued to be important to subsistence. [ABSTRACT FROM AUTHOR]

Azorella is a genus with 26 species of Azorelloideae (Apiaceae) that grow from Costa Rica to the subantartic islands, being distintive and dominant in different environments of the Andean Cordilleras from Venezuela to Patagonia. The species of Azorella that grow in Argentina have been revised taxonomically in a previous study. However, knowledge of the remaining species is fragmentary and uneven. The aim of this paper is to update and standardize the information of the 11 species of Azorella absent in Argentina and present in Bolivia, Chile, Colombia, Ecuador, Peru and/or Venezuela. We provide descriptions for those species and update distributional maps, and we solve nomenclatural and typification problems for 41 names, designating 2 type species, 16 lectotypes and 1 neotype. In addition, we provide 10 new illustrations, and an identification key for all the species of the genus. [ABSTRACT FROM AUTHOR]

Lythrum is a cosmopolitan genus with about 36 species of annual and perennial herbs. Lythrum salicaria, one of the most widely distributed species of this genus, grows at riverine sites in several countries, and is highly invasive outside its natural range. In this paper we report for the first time the presence of a spontaneous population of L. salicaria in Argentina. Specimens we collected at Las Go- londrinas, Chubut province, from which a morphological description was made. An identification key for all three Lythrum species that inhabit in Argentina is presented. [ABSTRACT FROM AUTHOR]

This paper confirms that the geographic range of Lygodium venustum includes north eastern Argentina, from the recent collection of specimens in the Provincial Park Moconá, Province of Misiones, and by the identification of herbarium material corroborating an ancient dubious citation of this species. This record represents the austral limit of the distribution of the species. Diagnostic characters are described and illustrated, and an identification key is provided, as well as reference material of Lygodium species from the Southern Cone of America. Lygodium venustum, L. pohlianum and L. palmatilobum are lectotypified and the last one is synonymized under Lygodium venustum. Lygodium hastatum, L. palmatilobatum and L. potentilloides are invalid names. [ABSTRACT FROM AUTHOR]

Mycena paranaensis and M. leaiana are very similar species from section Cespitosae, which have been confused by different authors. The aim of this paper is to clarify the species limits between M. leaiana and M. paranaensis. Mycena paranaensis is recorded for the first time for the Argentinean mycobiota, whereas M. leaiana is excluded. [ABSTRACT FROM AUTHOR]

Adiantum peruvianum (Pteridaceae) and Serpocaulon polystichum (Polypodiaceae) are recorded for the first time for Argentina in this paper. These new records were collected during trips to La Caldera and Chicoana department in Salta province. The diagnostic characters are described and illustrated, a keys for identification of species and distribution map are provided [ABSTRACT FROM AUTHOR]

This paper presents the archaeobotanical assemblage analysis carried out at two burial contexts from Western Tinogasta (Catamarca, Argentina). Las Champas and Bebé de La Troya sites show botanical macro remains that allow inquiring into the role of these vegetables in funerary practices and its implications within societies of Catamarca during the late period. Our aims are to characterize social practices involved in the presence of plant remains as grave goods, identifying cooking processing on these remains, trying in this way to go beyond the taxonomic identification. In both archaeological sites, plant macroremains and soil samples were analyzed with naked eye, stereo-binocular microscope, and transmitted light microscope. Archaeological plant samples were taxonomically identified based on diagnostic characters and post-harvest processing practices were detected following ethnoarchaeological features. At Las Champas site Cucurbita aff. maxima subsp. maxima and Chenopodium quinoa var. melanospermum seeds with processing features, together with a Lagenaria siceraria artifact were recovered. Grasses and cf. Zea mays microremains were present in soil samples. At Bebé de La Troya, Cucurbita aff. maxima subsp. maxima seeds and Prosopis sp. endocarps without processing features were identified. These results enable to suggest the presence of seeds, food and clothes as grave goods. These three ways of plant deposits show different intentional funerary practices as well as allow inquiring into culinary and agricultural aspects of later societies of Catamarca province. [ABSTRACT FROM AUTHOR]

Since 1965, El Palmar National Park, Entre Ríos, protects the largest remnant of Butia yatay palm savanna, a species-rich ecosystem threatened by human activity. To study the functioning of this ecosystem and to manage its preservation, it is necessary to have an adequate picture of its vegetation heterogeneity. In this paper, we present a phytosociological classification of the plant communities of this savanna, describe their structure, species composition and richness, and provide their distribution in the landscape. To stratify our data acquisition, we first mapped the major geomorphic units in this landscape. In the spring of 1999 and the following summer, we conducted complete inventories of plant species in 73 savanna stands with different fire histories distributed throughout the different geomorphic units. We used multivariate analysis and numerical classification techniques to group inventories in plant community types and species in floristic groups. Finally, we summarized the compositional differences among community types as a metric multidimensional scaling ordination. We defined seven community types, recognizable by combinations of 20 floristic groups. The pattern of similarities among these community types suggests that floristic heterogeneity is organized along two gradients, one associated with soil texture differences, and the other with differences in water input. Three of the community types, closely related to each other, are distributed on elevated fluvial terraces and interfluves, in correspondence with gradual differences in topography and soil. These community types undergo successional change due to woody encroachment triggered by cattle exclusion and maintained by scarcity of natural fires. The remaining four community types are strictly associated with rocky outcrops, sand deposits, or runoff pathways that interrupt the landscape matrix, with no apparent woody encroachment. [ABSTRACT FROM AUTHOR]

This paper integrates archaeobotanical research conducted in Antofagasta de la Sierra based on the identification, anatomy, and use of both present plant resources and archaeological plant remains, recovered during fieldwork between 1994 and 2000. Transects starting from the archaeological sites, the surrounding plant communities, and the species found are described. Characterization of present plant diversity also included the popular name and actual use of every species. Archaeological plant remains were identified by anatomy in comparison with present plant species in the studied area and their anatomical characters are here described and documented with digital images taken with compound microscope (bright field) and scanning electron microscope. Finally, discussion includes past and present use of every species recovered in the archaeological sites from Antofagasta de la Sierra, highlighting those aspects that imply change or continuity through time. [ABSTRACT FROM AUTHOR]

A taxonomic treatment of the genus Diplolepis is here presented. Based on molecular and biogeographical information recently published, this group is monophyletic and its geographical distribution is restricted to southwestern South America. The study comprised the analysis of herbarium specimens including nomenclatural types, supplemented with collections and observation of species in the field. This paper describes the variation in the morphology of the genus, including habit, stems, leaves, inflorescence, calyx, corolla, corona, gynostegium, pollinia, fruits and seeds. The morphological and distributional differences between Diplolepis and related genera are discussed. A key to differentiate the species of the genus is here given. Within each species we provide the valid name, synonyms, description of vegetative and reproductive morphological characters, geographical distribution, ecology, uses, common names, phenology, iconography and specimens examined. A lectotype is designated for D. viridis. [ABSTRACT FROM AUTHOR]

Sacciolepis (Poaceae, Panicoideae, Paniceae) is a pantropical genus composed by 23 species, mainly distributed in Africa, with some taxa in America, Asia and Australia. The aims of this work are to test the monophyly of Sacciolepis and to explore its infrageneric relationships. Thirty-one taxa and 80 morphological and anatomical characters, including continuous characters, were analyzed under the maximum parsimony criterion. The monophyly of Sacciolepis was corroborated and its diagnostic characters were discusssed. This paper is the first phylogenetic analysis of Sacciolepis. [ABSTRACT FROM AUTHOR]

Hieracium x stoloniflorum, native from central Europe and northwestern Russia and reported as a putative hybrid between H. aurantiacum and H. pilosella, is first documented for the Argentinian flora. This paper describes this weed and informs about its presence in Río Negro province. [ABSTRACT FROM AUTHOR]

This paper proposes the observation of anatomical features associated with water deficiency in wood as paleoenvironmental indicator. The analysis was applied to charcoal recovered in late archaeological contexts of Aguada in Ambato Valley, Catamarca (Argentina). Based on the correlation between the anatomical structure of wood and the habitat, the observations were done on present-day and archaeological samples of Geoffroea decorticans. Results show arid conditions in the study area at the end of the first millennium. [ABSTRACT FROM AUTHOR]

This paper analyzes the Zea mays racial variability and their relationship with the greater emphasis put on agricultural practices in the Southern Argentine "Puna" during ca. 1300-700 years BP, taking in account the archaeobotanical record of the sites "Cueva Cacao 1A" and "Bajo del Coypar II" ("Antofagasta de la Sierra", Catamarca, Argentina). Eight maize races were identified: Pisincho, Morocho, Morocho amarillo, Marrón, Harinoso Amarillo, Capia, Culli and Chullpi. This high biodiversity is a clear exponent about the introduction process of multiple maize races in the region. This process would have begun between the end of Formative Period in any moment among 1300 and 1000 years BP and becoming stronger in later moments. [ABSTRACT FROM AUTHOR]

In this paper, an ethnobotanical-ethnoarchaeological study of different local landraces of Cucurbitamaxima subsp. maxima, Cucurbitaceae, was carried on. The aim was to evaluate if different qualitative and quantitative seed characters of these local landraces, as well as those which came from plants resulting from cultivation or husbandry, get together or not in different morphotypes which materially reflect the diversity locally recognized, as well as local practices. The construction of these morphotypes is proposed as a way to recognize local landraces and different forms of Man - plant interactions in archaeobotanical samples. Domesticated plants are the result of actions derived from selection criteria socially built and transformed, therefore they can constitute different morphotypes which act as carriers of social meanings. For this reason we believe that an ethnoarcheological ethnobotany which generates models to contrast in paleoethnobotanical work will be a good option. Macroscopical morphological descriptors commonly used in archaeobotany were employed together with new micromorphological ones. It was concluded that quantitative micromorphological characters are the most adequate ones to create morphotypes which correspond with locally recognized landraces and with husbandry practices locally developed upon vegetable populations. [ABSTRACT FROM AUTHOR]

This paper is a taxonomic study of the Argentinean species of the genus Elaphoglossum (E. crassipes, E. gayanum, E. lindbergii, E. lorentzii, E. pachydermum, E. piloselloidesand E. yungense), based on morphological characters of the sporophyte. The history of the genus and the description of the species are provided, along with synonymy, comments on geographical distribution, habitat and a list of the studied specimens. Akey to identify the species is also given. [ABSTRACT FROM AUTHOR]

We studied the different ways of plant use among the Selknam from Tierra del Fuego (Argentina). In this paper we present the results obtained from the study of carbonized and non carbonized wood remains recovered at Ewan site, which was occupied at the beginning of the XXth century to celebrate an initiation ceremony. Results allowed a better understanding of the strategies of plant use in hunter- gatherer societies. The identification of the species used, and the analysis of their principal morphometric characteristics characterize the use of the "Ñire" (Nothofagus antarctica). This species, dominant in the surroundings, was used to build the dwelling as well as for fuel. For both uses, stems with suitable form and size were selected. Archaeobotanical results and their confrontation with the ethnographic data support the importance of vegetable resources within the socio-economic dynamics of the selknam society. Vegetable resources, beyond their use as food, were important in other aspects, such as technology, hut construction, fuel, and they certainly represented a considerable advantage in the area of the forests of the central zone of Tierra del Fuego. [ABSTRACT FROM AUTHOR]

This is the first complete, floristic analysis of the Asteraceae family from an extense, endangered, subtropical area of Argentina, covered by the Misiones Province. This study reports 88 genera, 345 species and 16 infraspecific taxa of Asteraceae from the two phytogeographic units of Misiones Province: "Selvas Mixtas" District, and "de los Campos" District. Nine species are recorded for first time, and 23 are included as probable records for this area. This paper includes keys for tribes, genera, species and infraspecific taxa, as well as a short discussion about distribution of tribes, genera and habits in relation to political departments or phytogeographic districts. Habit, status, distribution, habitat, vernacular names, uses, and vouchers are given for every taxon. Thirty two taxa are illustrated for the first time. [ABSTRACT FROM AUTHOR]

Digitaria cuatrecasasii, a new species from Honduras, Panamá, Colombia and Venezuela, is described and illustrated. The taxonomic position of D. cuatrecasasii is discussed, and its inclusion in sect. Leianthae is proposed. A comparative table and some remarks about the related taxa are included. Digitaria californica var. villosissima, D. corynotricha, D. curvinervis, D. fragilis and D. sacchariflora are reported for the first time for Colombia. Digitaria aequiglumis var. aequiglumis, D. argillacea var. nulliseta, D. ciliaris var. rhachiseta, D. costaricensis, D. eriantha, D. filiformis var. laeviglumis, D. lehmanniana var. dasyantha, D. parva, D. sacchariflora and D. ternata are cited for the first time for Venezuela. Digitaria cardenasiana and D. villiculmis are here sinonimized under D. corynotricha, and D. aequatorienis under D. pittieri. The following new records for countries are included as follows: D. argillacea var. argillacea for Perú, D. argillacea var. nulliseta for Guatemala, D. curvinervis for Ecuador and México, D. eriantha for Ecuador, D. fragilis for Nicaragua and Panamá, D. lehmanniana var. lehmanniana for Cuba and D. leucites for México. This paper includes synonymy, iconography, geographical distribution and ecology, vernacular names, specimens examined; a key for the identification of taxa is also given. Eleven species are illustrated for the first time. [ABSTRACT FROM AUTHOR]

This paper comprises a synopsis of the species of Alchornea growing in Argentina. These species are Alchornea castaneifolia, A. sidifolia and A. triplinervia, and one subspecies- A. glandulosa subsp. iricurana. A key to recognize the species and the subspecies, as well as descriptions, synonymy, illustrations and comments on the taxa studied are given. Alchornea sidifolia and A. glandulosa subsp. iricurana are new records for Argentina. [ABSTRACT FROM AUTHOR]

Schwartzia is a small genus of 17 species distributed in wet lowland forests or montane cloud forests from Costa Rica to southern Brazil, and also in the Lesser Antilles; it belongs to the Marcgraviaceae, a Neotropical family. Three species are considered in this paper for Brazil and one of these is described as a new species. The three taxa are endemic to Brazil. Each taxon is described; a key to identification of the species as well as information on distribution and ecology are also provided. [ABSTRACT FROM AUTHOR]

The genus Aristida is represented in northwestern Argentina by section Chaetaria with 23 taxa: 18 species and 5 varieties. Aristida nicorae sp. nov., A. victoriana sp. nov. and A. asplundii var. pauciflora var. nov. are described and illustrated. Aristida laxa var. longiramea and A. friesii are two new records for Argentina. Aristida achalensis var. tucumana, A. adscensionis var. bromoides, A. amplexifolia and A. mandoniana are considered synonyms. Aristida divaricata is excluded from the Argentine flora. This paper includes a key to recognize all species and varieties that grow in northwestern Argentina, as well as descriptions, synonymy, illustrations, geographical distribution and ecological observations. [ABSTRACT FROM AUTHOR]

This paper deals with a revised taxonomy of seven neotropical species of the genus Marattia (M. alata, M. cicutifolia, M. excavata, M. interposita, M. laevis, M. laxa y M. weinmanniifolia), based on morphological characters of the sporophyte, both vegetative and reproductive. A new and detailed description of the species is provided, along with synonymy, comments on habitat, geographical distribution and a complete list of the studied specimens. A key to identify the species is also given. [ABSTRACT FROM AUTHOR]

In this contribution, the tribe Lantaneae is considered in a broad sense. The morphology and typology of inflorescences in Lantana, Neosparton, Xeroaloysia, Acantholippia, Aloysia, Phyla, Bouchea, Chascanum, Stachytarpheta, Lampaya and Diostea are analyzed; Lippia has been treated in a previous paper. Inflorescences in Lantaneae belong to the polytelic type. Florescences are, in most species, spikes or sometimes spike-like racemes, varying in arrangement, spacing and number of flowers. Floral bracteoles are only present in Bouchea and Chascanum Sect. Chascanum. The most frequent pattern of the compound inflorescence is a homothetic (di) pleiobotryum with specialized long and short paracladia. This pattern, characteristic of Lantana, Phyla and Xeroaloysia, is also present in most species of Aloysia and one species of Acantholippia. Two Aloysia species have a paniculiform heterothetic pleiobotryum. Bouchea, Chascanum and Stachytarpheta have similar inflorescence. Most of their species inflorescences are dichasially ramified heterothetic pleiobotrya. Neosparton, Lampaya, Diostea and Acantholippia generally have monobotrya, which it could be interpreted as a result of reductive tendency related to the xeromorfic syndrome of these genera. The results of this study are compared with several taxonomic systems proposed for the Tribe Lantaneae. [ABSTRACT FROM AUTHOR]

The genus Digitaria is represented in Bolivia by 27 taxa: 22 species and 5 varieties. Digitaria argillacea var. nulliseta A. S. Vega & Rúgolo var. nov. is described and illustrated. Digitaria catamarcensis, D. ternata, D. setigera and D. aequiglumis var. laetevirens are reported for the first time for the country and D. laxa constitutes a dubious report for Bolivia. Digitaria gerdesii var. boliviensis and D. similis are recognized and confirmed for Bolivia and the following species are excluded: Digitaria neesiana, D. sanguinalis, D. violascens and D. corynotricha. Digitaria lanuginosa and D. setigera are illustrated with details and Digitaria fragilis is illustrated for the first time. This paper includes synonymy, iconography, geographical distribution and ecology, uses, vernacular names, specimens examined, a key for the identification of taxa is also given. [ABSTRACT FROM AUTHOR]

The genus Tibouchina, Melastomataceae, is mainly distributed in tropical and subtropical regions of the Americas and includes nearly 350 species. Seven taxa are considered in the present paper and two of these are new records for the Argentinian flora. Each taxon is described and ilustrated. A key for the identification of the species as well as information on distribution and ecology is also provided. [ABSTRACT FROM AUTHOR]

The genus Baccharis is represented in Argentina by 96 species, the infrageneric classification of which is presented in this paper. A succinct summary of the history of Baccharis infrageneric taxonomy is provided. The 96 Argentine species are placed into 15 sections: Angustifoliae, Aristidentes, Baccharis, Caulopterae, Cuneifoliae, Cylindricae, Discolores, Molinae, Nitidae, Oblongifoliae, Paniculatae, Pedicellatae, Pseudobaccharis, Subliguliflorae -sect. nov.- and Trinervatae. These sections are briefly described, and a key to differentiate them is given. Twelve out of the 96 species are positioned into the infrageneric classification system for the first time, whereas 42 species which had been previously classified are here relocated to other sections. Twenty-two generic, subgeneric, sectional and subsectional names are considered as new synonyms. The relationships among the sections are discussed. [ABSTRACT FROM AUTHOR]

The genus Bothriochloa Kuntze, which belongs to subfamily Panicoideae, tribe Andropogoneae, is mainly distributed in tropical and subtropical regions, with nearly 35 species throughout the world. Twenty six taxa of the genus were treated in the present paper, including 22 species, 2 subspecies and a variety. Within each taxa, information is given about vernacular names, iconography, distribution and ecology, chromosome numbers, a list of representative material and illustrations. A key for the identification of taxa is also provided. [ABSTRACT FROM AUTHOR]

This paper deals with the interpretation, description and typological characterization of the inflorescences of the following genera of the tribe Petreeae Briq.: Petrea L., Xolocotzia Miranda and Recordia Moldenke. All of them have a polytelic type of synflorescence. Florescences of all genera are racemes with decussate bracts. The heterothetic diplobotryum is present in Recordia and also in several species of Petrea. Truncation of the main florescence has been found in P. maynensis J. Huber, P. volubilis L. and P. pubescens Turcz. giving rise to an homothetic diplobotryum. Suppression of the enriching zone occurs in Xolocotzia, Recordia and some species of Petrea. Xolocotzia has monobotrya and reduction of flower number within the florescences. In the monobotrya the pair of leaves preceding the basal internode is bracteose and bears axillary resting buds. In the heterothetic diplobotryum this node represents an intercalar inhibition zone. Some Petrea species show aborted accessory paraclades. These arise from the accessory axillary buds of the enrichment zone. According to this study, the heterothetic pleiobotryum has been considered as a primitive or central form, from which monobotrya derived through processes of suppression of the enrichment zone, and homothetic pleiobotrya, by suppression of the main florescence (truncation). The use of inflorescence characters for a cladistic analysis accomplished by Rueda (1994) for the genus Petrea, are discussed. [ABSTRACT FROM AUTHOR]

This paper deals with the interpretation, description and typological characterization of inflorescences in the genus Lippia L. This genus comprises 160 species, mainly distributed in tropical and temperate America, with only a few species growing in the Old World, of which 60 have been studied. The inflorescences are of compound polytelic type, with bracteate capituliform spikes as florescences. The phyllotaxis, form, size and colour of the bracts have taxonomic value, these characters correspond with the sections of the genus. In section Dipterocalyx, the inflorescences are bracteate or frondose-bracteate heterothetic pleiobotrya; in the remaining sections the inflorescences are homothetic pleiobotrya. Series Corymbosae and Paniculatae, and some species of section Dioicolippia, have bracteate or frondose-bracteate inflorescences, while the remaining sections have frondose ones. Section Goniostachyum and subsection Mexicanae have numerous paraclades per axile, while the other sections have 1-2 paraclades per axile. Section Pseudoaloysia (Lippia lasiocalycina Chem.) is characterized by the production of flowers in two stages: first, on bracteate brachyblasts with proliferation and the second on frondose macroblasts, which are originated by the first brachyblasts. The heterothetic pleiobotra have been mentioned as the primitive form from which other inflorescences were derived. If this hypothesis is correct, the species of section Dipterocalyx may possibly be the ancestral group, from which the homothetic pleiobotrya of other sections derived. [ABSTRACT FROM AUTHOR]

This paper deals with a taxonomic revision of the South American species of the genus Piptochaetium. This systematic treatment includes a discussion of the morphological and anatomical characteristics of the genus, together with a key to identify the species treated in 2 sections: Podopogon (Raf.) Parodi (13 species) and Piptochaetium (14 species, 2 subspecies and 2 varieties). For each species, a description, synonymy, geographical distribution, illustrations and photographs of the characters with taxonomical value are given. Some species, varieties or forms have been reduced to synonymy: P. panicoides f. subpapillosum, P. grisebachi, P. stipoides var. chaetophorum, P. stipoides var. parviflorum, P. stipoides var. purpurascens, P. stipoides var. verruculosum and P. uruguense var. microcarpum. [ABSTRACT FROM AUTHOR]

This paper presents the comparative analysis of the seed morphology and stem structure of 12 species of Justicia Houst. ex L. from the northeastern of Argentina. Even though these species belong to four different sections, all of them have a well developed endodermis in the stem, and a normal structure except in J. laevilinguis (Nees) Lindau that is polystelic. In agreement with Graham (1988) J. dumetorum Morong and J. squarrosa Griseb. belong to sect. Simonisia; J. goudotti V.A.W. Graham, J. lythroides (Nees) V.A.W. Graham, J. oblonga (Nees) Lindau and J. ramulosa V.A.W. Graham to sect. Chaetothylax; J. brasiliana Roth and J. floribunda (C. Koch) Wassh. to sect. Plagiacanthus and J. laevilinguis to sect. Dianthera subsect. Dianthera. Taking into account the analized characters, three species, two of which were previously considered as of uncertain taxonomic position, are tentatively placed within the infrageneric classification of Graham (1988): J. tweediana Griseb. in sect. Plagiacanthus, J. axillaris (Nees) Lindau in sect. Chaetothylax and J. comata (L.) Lam. in sect. Dianthera subsect. Dianthera. [ABSTRACT FROM AUTHOR]

The pollen of Paspalum unispicatum (Scribn. et Mer.) Nash shows some anomalous types, such as: dyads and tetrads with partially divided monads, inaperturates, anomalous monoaperturates, biaperturates and triaperturates grains. In this paper the morphometric features of "normal" and anomalous pollen grains were compared, and their potential viability tested with aceto-carmine coloration. A comparative analysis of the pollen of upper and lower flowers showed that the abnormalities are independent of the position of the flowers. These anomalous types were also found in Paspalum decumbens Rottb., and Paspalum urvillei Steud. The anomalous pollen grains probably result from meiotic chromosome abnormalities in these tetraploid species. [ABSTRACT FROM AUTHOR]

This paper deals with the interpretation, description and typological characterization of the inflorescences of the genera belonging to the tribe Verbeneae. These genera are: Glandularia Gmelin, Hierobotana Briquet, Junellia Moldenke, Tamonea Aublet, Verbena Linné and Urbania R. A. Philippi, all of them represented in South America. All the cases belong to the polytelic type of synflorescences. Florescences of almost all genera are dense spikes with decussate bracts. Only Tamonea has loose, spiciform racemes with disperse bracts. Floral prophylls are always absent. The heterothetic pleiobotryum is the most frequent branching form, present in Verbena, Glandularia and Hierobotana. Urbania and Junellia have monobotrya. Homothetic pleiobotrya characterize all species of Tamonea. Heteroblastic development of the branches can be observed in several species of Junellia. In these cases flowering can be restricted to the brachyblasts, a frequent specialization in woody plants. The heterothetic paniculiform pleiobotryum has been mentioned for several families of the Angiospermae as a primitive or central form, from which other forms derived through processes such as condensation, reduction and truncation. In Verbeneae this non specialized "paniculodium" is present in Verbena and Glandularia. Condensation of the florescences, to compose more or less functionally discrete subunits, appears in Verbena ser. Pachystachyae and Glandularia subgen. Paraglandularia. Reduction of the enriching zone occurs in Urbania and most Junellia species. Such reduction and decrease of flower number in the florescences could be related to the xerophyllous nature of these species. Truncation of the main florescence, such as the homogenization and racemization of the distal paracladia, have been produced in Tamonea giving rise to an homothetic pleioraceme. Tamonea shows few affinities with the remaining genera of Verbeneae. It differs from them in several inflorescence characters and gynoecial features previously studied by other authors. Because of all these characters, the place of this genus within the Verbenoideae should be reconsidered. [ABSTRACT FROM AUTHOR]

This paper deals with the epiphytic algae found in a channel and in an artificial pond in Estación Experimental INTA Delta (Buenos Aires, Argentina). These algae are in relation with a carp population that feeds on them in their early stages. A total of 21 taxa were identified. One was a new taxon, Uronema elongatum Hoodgetts var. robustus L. Mercado et Vigna, and six are new records for Argentina. Among the Cyanophyceae, the 60% were associated algae whereas the rest were epiphytic on emergent macrophytes. The coccoid Xantophyceae were found on filamentous Chlorophyceae, whereas the filaments themselves were epiphytic on emergent macrophytes. [ABSTRACT FROM AUTHOR]

The diatom flora of Paso de las Piedras reservoir and affluents, Buenos Aires Province, was studied. In this paper we present those species and varieties that belong to the families Diatomaceae, Achnathaceae and Eunotiaceae. Each taxon, studied with light and/or scanning electron microscope, is described and ilustrated. The taxonomic information is completed with references about geographic distribution and ecological requirements. Diatoma moniliforme Kützing, a new record for Argentina and South America is included. A brief characterization of the study area and methodology are also given. [ABSTRACT FROM AUTHOR]