NOTAS
Phoradendron Argentinum (Viscaceae), new mistletoe for the brazilian flora and its general distribution in South America
Greta A. Dettke, Luís F. P. Lima & Jorge L. Waechter
Programa de Pós-Graduação em Botânica, Instituto de Biociências, Av. Bento Gonçalves, 9500 - Bloco IV - Prédio 43433 - sala 205, Universidade Federal do Rio Grande do Sul, Brazil; gretadet@yahoo.com.br (author for correspondence)
Abstract.
The first collection of the mistletoe Phoradendron argentinum (Viscaceae) for the Brazilian flora is reported. A brief description, a key including the taxonomically closest species, photographs and a distribution map of the species are given. Lectotype of P. argentinum is here designated.
Keywords. Brazil; Flora; Mistletoes; Phoradendron; Viscaceae.
Resumen.
Phoradendron argentinum (Viscaceae), una nueva hemiparásita para la flora del Brasil y su distribución en América del Sur.
Se cita por primera vez la especie hemiparásita Phoradendron argentinum (Viscaceae) para la flora de Brasil. Se presenta una descripción de la especie, una clave para diferenciarla de especies próximas, fotografías y mapa de distribución para América del Sur. Se designa un lectotipo para esta especie.
Palabras clave. Brasil; Flora; Hemiparásitas; Phoradendron; Viscaceae.
INTRODUCTION
Phoradendron Nutt.
(Viscaceae) is a neotropical mistletoe genus with approximately 230 species
(Kuijt, 2003, 2009; Caires & Proença, 2007). Brazil is one of the diversity
centre of the genus, with about 65 species distributed in all major biome types
of the country (Caires & Dettke, 2010) and occurring as hemiparasite on a
great number of different host plant species.
During an ongoing inventory of Santalales in southern Brazil, Phoradendron
argentinum Urb. was collected in the southern part of Rio Grande do Sul
State. We present a botanical description and a map showing the expanded
geographic distribution of this species in South America.
RESULTS
Phoradendron argentinum Urb., Bot. Jahrb. 23, Beibl. 57: 14. 1897. TYPE: Argentina, Catamarca, Chacarita de los Padres, XI-1872 (fr), G. Hieronymus 419 (lectotype F! (F Neg 70633) here designated; duplicates B (destroyed), CORD, GOET, K!). Figs. 1-2.
Fig. 1.
Phoradendron argentinum. A, a mistletoe
infestation on an emergent tree of Ruprechtia laxiflora Meisn.
(Polygonaceae). B, branch with immature fruits.
C, glaucous young shoots. D, detail of
inflorescences with staminate (arrows) and pistillate flowers.
E, detail of fruits. B and D, Dettke & Lima 181
(ICN); C and E, Dettke et al. 496 (ICN).
Fig. 2. Geographic distribution of Phoradendron argentinum in South
America.
For synonyms see Kuijt (2003: 93).
Plants percurrent, green, the young shoots often glaucous, erect, up to 40 cm, monoecious. Stem strongly quadrangular to keeled, intercalary cataphylls absent, internodes short, 2-4 cm; 1(-2) pairs of basal cataphylls. Leaves 3-nerved, nerves inconspicuous, 2-3 x 1-1.5 cm, lanceolate, apex acute and minutely apiculate, base acute. Inflorescences with 2 sterile basal articulations and 2(-3) floriferous segments, each flower area with one terminal staminate flower and two lateral pistilate flowers. Fruits globose-ovoid, white with a reddish tip, pericarp tuberculate at the apex, petals erect at fruit.
Notes. Urban (1897) described Phoradendronargentinum and P. pruinosum in the same publi- cation, calling attention to the high degree of affi- nity between the two taxa. Later, Trelease (1916) recognized P. meliae as a distinct species, which was later treated as a synonym of P. argentinum by Abbiatti (1946). This author also called the attention to the close affinity and the problematic distinction between P. argentinum and P. pruinosum, based mostly on the size and shape of the leaves. Kuijt (2003) recognized P. argentinum as a valid name for a single species, thus considering P. meliae and P. pruinosum as synonyms of the former. A lectotype of P. argentinum at B herbarium was designated by Trelease (1916). This material was destroyed; consequently, a new lectotype is here designated.
Distribution and
habitat. The species occurs in north-western to south-eastern South
America, from southern Bolivia, Paraguay and northern Argentina (Kuijt, 2003).
Rizzini (1956) cited P. argentinum for Uruguay (Rio Negro, Rincón de
Pomia, J. Chebataroff. s.n., MVM 15.359); however, Kuijt (2008) considered this
occurrence doubtful for the country. We could not examine the material cited by
Rizzini (1956), but we believe the occurrence in Uruguay is highly probable
owing to the proximity of the international border and the continuity of
similar environments.
In Brazil, the species is now known from narrow strips of gallery forests which
are typical in the Pampas biome or biogeographic province. In these forests the
species was observed only on large emergent (20-25 m) trees of Ruprechtia
laxiflora (Polygonaceae). The mistletoes can be seen in the landscape as
more or less dense rounded clumps along the smaller branches of the host plants
(Fig. 1A). Like several other species of
Phoradendron, the haustorial system has a single point of contact with
the host (Kuijt, 1969), this causing a hypertrophy of the branches up to 30 cm
in diameter.
Abbiatti (1946) reported 18 species of host plants for Phoradendron
argentinum (including P. pruinosum) in Argentina, comprising
species of Anacardiaceae (Schinopsis Engl.), Fabaceae
(Anadenanthera Speg. (=Piptadenia Benth.)),
Geoffroea Jacq. (=Gourliea Gill. ex Hook.),
Mimozyganthus Burkart, Prosopis L., Vachellia Wight
& Arn. spp. (=Acacia Mill.), Nyctaginaceae (Bougainvillea
Comm. ex Juss., Pisonia Plum. ex L. ), Achatocarpaceae
(Achatocarpus Triana), Polygonaceae (Ruprechtia C. A. Mey. spp.),
Rhamnaceae (Ziziphus Mill.), Cannabaceae (Celtis L. sp.), and
Zygophyllaceae (Porlieria Ruiz & Pav.) and the exotic Melia
azedarach L. (Meliaceae). Based on this extensive list, the species can be
indicated as a generalist in relation to host plants.
Examined material from Brazil
BRAZIL. Rio Grande do Sul. Bagé, Estância Mato do Recreio, Arroio Piraí, 31° 33' 9.69" S, 54° 24' 41.86" W, 21-III-2009 (fl, fr), on Ruprechtia laxiflora Meisn. (Polygonaceae), Dettke & Lima 181 (ICN); Quaraí, 30° 23' 5.37" S, 56° 7' 21.17" W, 4-XII-2010 (fl, fr), on Ruprechtia laxiflora Meisn. (Polygonaceae), Dettke et al. 496 (ICN, MBM, PACA).
Key to monoecious species of Phoradendron with 3 flowers per fertile bract in Southern Brazil
1. Plants dichotomous
branched . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . P. craspedophyllum
1. Plants percurrent . . . . . . . . . . . . . . . . . . . . . . . . . . .2
2(1). Leaves obovate, the apex obtuse; fruit globose, pericarp tuberculate . .
. . . . . . . . . . . . . P. mucronatum
2. Leaves lanceolate, the apex acute or rounded, minu- tely apiculate; fruit
ovoid, smooth or with a tuberculate pericarp only at the apex . . . . . . . . .
. . . . . . . . . . . . .3
3(2). Stems terete; leaves up to 4 x 1.5 cm; fruit always smooth throughout . .
. . . . . . . . . . . . . . . P. reductum
3. Stems strongly quadrangular to keeled; leaves up to 3 x 1.5 cm; fruit with
pericarp tuberculate at the apex........ . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .P. argentinum
Representative specimens examined of Phoradendron argentinum
ARGENTINA. Catamarca. Andalgalá, 26-XI- 1972, Cantino 510 (CORD); Capital, 04-X-1973, Hunziker 22330 (CORD); Santa Rosa, 16-XI- 1984, Subils 3640 (CORD). Chaco. 1915, Jörgensen 2227 (MO). Córdoba. Cólon, 11-V-1957, Ariza Espinar 958 (CORD). Corrientes. Esquina, 14-III-1975, Krapovickas et al. 27742 (MO); San Cosme, 16-VI-1967, Krapovickas & Cristóbal 12999 (MO). Formosa. Laishi, 18-II-2000, Di Giácomo 453 (CTES). Jujuy. Capital, 16-XI-1980, Cabrera et al. 32082 (MO); Ledesma, 16-IX-1976, Cabrera et al. 27893 (MO); San Pedro, 04-X-1929, Venturi 9711 (MO); Santa Bárbara, 13-XI-2002, Zuloaga et al. 7575 (SI). La Rioja. Capital, 04-III-1944, Hunziker 5050 (CORD). Salta. Orán, 23-XI-1927, Venturi 5600 (MO). Santa Fe. General Obligado, 30-XII-1972, Quarín 759 (MO). Santiago del Estero. Choya, 11-VI-1982, Hunziker et al. 24345 (CORD); Guasayán, 11-VI-1982, Hunziker et al. 24279 (CORD); Pellegrini, 31-XII-1927, Venturi 5736 (MO).
BOLIVIA. Chuquisaca. Luis Calvo, 18-V-1992, Killeen et al. 4178 (MO). Cochamamba. Campero, 19-III-1999, Antezana 1161 (BOLV). Santa Cruz. Andres Ibáñez, 30-X-1998, Mani 38 (USZ); Cordillera, 16-VII-1998, Fuentes & Navarro 2566 (MO).
PARAGUAY. Alto Paraguay. 14-II-1999, Zardini & Godoy 50338 (MO). Boquerón. 12-XII-1998, Zardini & Duarte 49612 (MO). Central. 04-III-1993, Zardini & Guerrero 35347 (MO). Presidente Hayes. 18-VII-1995, Mereles & Degen 6070 (MO).
URUGUAY. Río Negro. Rincón de Pomia, Chebataroff s.n. (Herb.Osten 15359).
BIBLIOGRAPHY
1 Abbiatti, D. 1946. Las Lorantáceas argentinas. Revista del Museo de La Plata, Botánica 28: 1-110.
2 Caires, C. S. & C. E. B. Proença. 2007. Two new synonyms and a species reinstated in Phoradendron Nuttall (Viscaceae). Acta Botanica Brasilica 21: 379-382.
3 Caires, C. S. & G. A. Dettke. 2010. Santalaceae, in R. C. Forzza et al. (eds.), Catálago de Plantas e Fungos do Brasil, vol. 2, pp. 1603-1606. Rio de Janeiro: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro.
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5 Kuijt, J. 2003. Monograph of Phoradendron. Systematic Botany Monographs 66: 1-643.
6 Kuijt, J (rev.). 2008. Viscaceae, in F. O. Zuloaga, O. Morrone & M. J. Belgrano (eds.), Catálogo de las plantas vasculares del Cono Sur (Argentina, Sur de Brasil, Chile, Paraguay y Uruguay), vol. 3, pp. 3169-3172. Saint Louis: Missouri Botanical Garden Press.
7 Kuijt, J. 2009. Miscellaneous mistletoe notes, 48-60: Descriptions of twelve new species of Loranthaceae and Viscaceae. Brittonia 61: 144-162.
8 Rizzini, C. T. 1956. Pars specialis prodromi monographie Loranthacerum Brasilie terrarumque finitimarum. Rodriguésia 31: 87-234.
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10 Urban, I. 1897. Loranthaceae. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 23: 1-16.