DCMPCSITAE # NCWSLETTCC Number 43 15 December 2005 Scientific Editor: Bertil Nordenstam Technical Editor: Gunnel Wirenfus Nohlin Published and distributed by The Swedish Museum of Natural History, Department of Phanerogamic Botany, PO. Box 50007, SE-104 05 Stockholm, Sweden ISSN 0284-8422 Susana E. Freire, Gisela Sancho, Estrella Urtubey, Nestor Bayon, Liliana Katinas, Daniel Giuliano, Diego Gutierrez, Alcides A. Saenz, Laura Iharlegui, Claudia Monti, and Gustavo Delucchi Catalogue ofAsteraceae of Chacoan Plain, Argentina BOTANICAL Ga.^DEN Comp. Newsl, 43. 2005 CATALOGUE OF ASTERACEAE OF CHACOAN PLAIN, ARGENTINA Susana E Freire'^, Gisela Sancho^^, Estrella Urtubey\ Nestor D Bayon^, Liliana Katinas'^, Daniel A. Giuliano', Diego G. Gutierrez', Alcides A Saenz^, Laura Iharlegui', Claudia Montr, and Gustavo Delucchi''^. Abstract The present catalogue documents 325 species of Asteraceae known to occur in the Chacoan plain of Argentina Twelve taxa are here first recorded for this area From the total of the Chacoan species of Asteraceae, ca 120 have been employed for economic uses The Asteraceae of the Chacoan plain of Argentina are presented following a catalogue format, including synonyms, infraspecific taxa, iconography references, vernacular names, habit, flowering period, phytogeographical and political distribution, uses, and vouchers for each taxa. Keys to tnbes, genera, species and varieties or subspecies are also provided. KEY WORDS: Asteraceae, Argentina, Chacoan plain. Catalogue ACKNOWLEDGEMENTS We appreciate the helpful contributions of Bertil Nordenstam, and the valuable comments of John Pruski on the first version of the manuscript. We are grateful for the cooperation of the curators of herbaria mentioned. This study was supported by the Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Argentina ' Division Plantas Vasculares. Museo de la Plata. Paseo del Bosque s.n., BI900FWA La Plata. Argentina. E-mail: freire@fcnym. unlp.edu. ar " Area de Botanica, Departamento de Biologia y Ecologia, Facultad de Ciencias Agrarias y Forestales. Universidad Nacional de La Plata, calie 60 entre 1 16 y 118, 1900 La Plata, Argentina. ' Facultad de Ciencias Naturales \ Museo. Universidad Nacional de La Plata, Paseo del Bosque s.n.. 1900 La Plata, Argentina. Introduction The present catalogue documents 325 species of Asteraceae known to occur in the Chacoan plain of Argentina Twelve taxa not published in the regional floristic treatments of 2 Comp. Newsl. 43. 2005 Asteraceae (Cabrera, 1963, 1971b, 1974, 1978), Flora Fanerogamica Argentina (Ariza Espinar & Delucchi, 1998, Ariza Espinar & Urtubey, 1998; Arlza Espinar, 1997, Bartoli & Tortosa, 2003; Cabrera & Freire, 1997; Cabrera, Freire & Ariza Espinar, 1999; Cerana, 1997; Freire, 1995, 1996, Giuliano, 2000; Katinas, 1995, 1996; Ariza Espinar & Petenatti, 1997; Sancho, 1996; Sancho & Ariza Espinar, 2003;Tortosa & Bartoli, 2003; Urtubey, 1996), and Catalogo de las Plantas Vasculares de la Republica Argentina II (Zuloaga & Morrone, eds 1999) are here first recorded for this area. From the total of the Chacoan species of Asteraceae, ca 120 have been employed for economic uses, including medicinal, edible, or ornamental. The area The Chacoan plain ("Llanura chaquena"), also called Chacoan Park ("Parque chaqueno") (Ragonese & Castiglioni, 1970), constitutes a natural area (Morello, 1967; Moreno & Adamoli, 1974), and belongs to Chacoan province of the Chacoan domain within the Neotropical region (Cabrera & Willink, 1973). It occupies most of the Chacoan phytogeographlcal province with the exception of the slopes of the Subandean and Pampean mountain ranges in the western side of the area Chacoan plain extends in twelve Argentinian provinces, i.e. southeastern Jujuy, eastern Salta, Formosa, Chaco, Santiago del Estero, eastern Tucuman, eastern Catamarca, eastern La Rioja, northeastern San Luis, northern and center Cordoba, northern Santa Fe and western Cornentes (Figure 1). This big plain slightly descends in a northeastern-southwestern and northern-southern direction. The climate is humid in the east and becomes somewhat arid towards the west where the rainfall decreases from 1000 to 500 mm/year Therefore, in the eastern side of the area lagoons and streams are common whereas in the western side salines are abundant The typical vegetation is the xerophilous evergreen forest, with grasses, cacti, and terrestrial bromeliads There are also palm groves, savannas, and halophilous shrubby steppes (Cabrera, 1970). The Chacoan plain constitutes one of the few areas of the world where the tropical and the temperate areas are continuous and have not a desert between them. It is probably the only place in the world where the tropical-temperate thermic gradient, and the transition from tropical to temperate soils can be observed along a wide range of homogeneous bands of rains, topography, and continentality (Morello, 1967). The vegetation According to Cabrera's classification (1971a, 1976), the area under study comprises three phytogeographlcal districts: a) Chacoan Oriental, b) Chacoan Occidental, and c) Savannas. The Chacoan Oriental district ranges from eastern Formosa and Chaco, northern Santa Fe, and northwestern Corrientes It is a hot and wet plain crossed by numerous rivers and streams. The climax community is represented by forests of "quebracho Colorado" Comp. Newsl 43. 2005 3 {Schinopsis balansae), the forestal economically most important species in Argentina, and forests of "quebracho bianco" (Aspidosperma quebracho-bianco) There are other representative arborescent species (eg, Astronium balansae, Caesalpinia paraguariensis, Gleditsia amorphoides. Patagonula amehcana. Ruprechtia laxiflora. Tabebuia impetiginosa). shrubs (eg, Acacia praecox, Prosopis ruscifolia). cacti (eg, Harnsia bonplandii, Monvillea cavendischii, Opuntia anacantha var retrorsa), grasses, and spiny bromeliads {Aechmea disticachantha, Bromelia serra. Dyckia ferox). There are also many edaphic communities of palms (Coperntcia alba) Due to the inclination of the area, the water courses in some places become irregular and originate wetlands (with e g , Eichhornia spp , Pontedena spp ) and swamps with marshy vegetation (eg, Cyperus giganteus, Panicum pnonitis. Paspalum intermedium, Sorghastrum setosum) The species of Asteraceae are found in diverse habitats, for example Eupatonum christieanum. Gnndelia scorzonenfolia, and Vernonia rubricaulis inhabit forests of "algarrobo negro" {Prosopis nigra) and "churqui" {Acacia caven), Eupatonum christieanum and Gnndelia tehuelches inhabit the "caranday" palm groves (Copernicia alba) and forests of "algarrobo bianco" {Prosopis alba), also, the "aliso" or "pajaro dodoneifolia and Baccharis salicifolia are bobo" ( Tessaria integrifolia) together with Tessaria frequent in river banks The Chacoan Occidental district ranges western Formosa and Chaco, Santiago del Estero, and eastern Jujuy, Salta, Tucuman, Catamarca, La Rioja, northwestern Cordoba, and northern San Luis The western limit of this district reaches 500 m elevation, beyond this altitude the mountain ranges are found Comparing to the Oriental district, the Chacoan Occidental district is drier being the evapo-transpiration the highest in the country (Ragonese & Castiglioni, 1970) The plain is covered by forests spotted with steppes or "pampas", spiny shrubs, and cacti The climax community is the forest of "quebracho Colorado santiagueno" {Schinopsis lorentzii), "quebracho bianco" {Aspidosperma quebracho-bianco), and "palo santo" {Bulnesia sarmientoi) There are also other significant tree species (eg, Caesalpinia paraguariensis. Cercidium praecox, Ceiba speciosa, Prosopis kuntzei. Ziziphus mistol), shrubs (eg. Acacia caven. A. furcatispina, Cappans tweediana). cacti (eg, Opuntia quimilo, Pereskia sacharosa. Stetsonia coryne), grasses (Digitana sanguinalis. Gouinia latifolia, Setaria pan/iflora), and terrestrial bromeliads {Bromelia hieronymi. B. serra, B urbaniana). Communities of palms {Trithrinax biflabellata), "water hyacinth" {Eichhornia spp), and marshes with Panicum pnonitis . Scirpus californicus are also found Salt mines are common in this area which are covered by an halophilous vegetation {Heterostachys ritteriana, Allenrolfea patagonica) Among the typical Asteraceae, Holocheilus hieracioides and Trixis cacalioides inhabit the "quebrachales" (forest of "quebracho"), Cyclolepis genistoides grows among the cacti, and Tessaria integrifolia grows associated with Salix humboldtiana (Salicaceae) in sandy nver banks. The Savannas district is a narrow area that occupies northern Santa Fe between the Oriental and Occidental districts. The climax community is the savanna of Elionorus muticus together with grasses (e.g., Bothriochloa barbinodis, Leptocoryphium lanatum, Schizachynum 4 Comp. Newsl. 43, 2005 condensatum. Sorghastrum pellitum), herbaceous dictotyledons (eg., Desmanthus virgatus, Glandularia peruviana), and Isolated trees (Geoffroea decorticans. Prosopis affinis, P. nigra). Other communities of this district are the savannas of Leptochloa chlondiformis on salty soils and Spartina argentinensis in wetlands Among the Asteraceae, Aspilia montevidensis var setosa. Bacchans artemisioides, B. articulate, S. coridifolia, Pterocaulon cordobense. and Vernonia incana can be found. Biodiversity and conservation Given the topographic and climatic characteristics of the Chacoan plain, this is not considered as one of the nchest areas of Argentina regarding the number of species or the endemic taxa. There are some