Two new synonyms and a species reinstated in Phoradendron Nuttall ( Viscaceae ) 1

(Two new synonyms and a species reinstated in Phoradendron Nuttall (Viscaceae)). Three taxonomic changes are proposed based on intensive collecting of Viscaceae within the Distrito Federal, Brazil. Phoradendron andersonii Rizzini, previously a synonym of P. perrottetii (DC.) Eichler is reinstated based on the following combination of characters: young internodes compressed with sharp angles at the distal ends, short spikes to 2.5 cm long, articles with intermixed male and female flowers, biseriate flowers, and dirty yellow fruits. Phoradendron irwinianum Kuijt is synonymized under P. apiciflorum Rizzini, previously known only from the type from western Minas Gerais. Finding of the type collection of P. brachyklados Rizzini, incorrectly quoted in the protologue, led to the synonymization proposal of this species under P. hexastichum (DC.) Grisebach.


Introduction
A detailed study of the Viscaceae of the Distrito Federal, Brazil, was undertaken between 2001 and2003.Eighteen of the 21 species were observed in the field and collected together with their hosts, and nomenclatural types or their images were studied (Caires & Proença 2005).
Since the Flora do Distrito Federal precludes publication of new synonyms or detailed taxonomic discussions elsewhere, two new synonymizations are presented, and one former synonym reinstated in this paper.These proposals are related to previous Kuijt (2003) statements, which are discussed below: 1) the synonimyzation of P. andersonii Rizzini under P. perrottetti (DC.)Eichler; 2) the description of P. irwinianum Kuijt; and 3) the status of nomen dubium attributed to P. brachyklados Rizzini.

Material and methods
Specimens were collected in Cerrado, Cerradão, Mata ciliar, Mata de galeria and Mata mesofítica.Phoradendron collections deposited in the CEN, IBGE, HEPH, RB and UB herbaria, including types, were also studied.Complete lists of examined material are available in Caires & Proença (2005).Images available at the New York Botanical Garden (2002) and National Herbarium Nederland (2002) sites were also examined.
Scientific names which appear between square brackets after cited names refer to the name accepted by Kuijt (2003).Complete lists of synonyms for the species are also to be found in Kuijt (2003).
[=P. bilineatum Urb.].In the field, it is very similar to both P. lanceolato-ellipticum (Pohl) Eichler [=P.interruptum (Jackson) DC.] and P. perrottetii (DC.)Eichler, particularly in leaf shape.This similarity led Kuijt (2003) to relegate P. andersonii to the synonymy of P. perrottetii, noting that he had seen specimens of P. perrottetii with inflorescences which were similar to those of P. andersonii.However, Kuijt (2003) noted this as a provisional synonym, indicating he did not consider the case closed.We have not been unable to examine the same P. perrottetii specimens cited by Kuijt, but during our study nine new collections of P. andersonii and 26 of P. perrottetii were made, besides field observations of both species.These taxa are clearly distinct, their differences summarized in Table 1.
Based on these differences, and having analyzed the types of P. andersonii and P. perrottetii, we conclude that P. andersonii is distinct from P. perrottetii and should be maintained.
Selected During our study four collections of P. apiciflorum were made.In our opinion, these collections and the types of P. apiciflorum and P. irwinianum belong to a single species, characterized by being a monoecious plants, with large, imperfectly acrodromous, coriaceous leaves up to 10 cm long, 1-2(-9) spikes per leaf axil, short spikes 1,3-4 cm long, with 4 articles, the articles with 6-10(-14) biseriate flowers, the male flowers dispersed throughout the articles, and ovoid, yellowgreen fruits with closed tepals.Geographically, the Distrito Federal population is c. 300 km NNW of the type locality of P. apiciflorum, but the highland habitat is more or less continuous between the Distrito Federal highlands and the Serra de Paracatu, Minas Gerais.Furthermore, one of the specimens of P. apiciflorum (Heringer et al. 2927) cited by Kuijt (2003) and the type of P. irwinianum were found growing on Roupala sp.(Proteaceae).Within the Distrito Federal, Roupala montana Aubl. is common in cerrado (woodland savannas), while possibly distinct Roupala brasiliensis Klotzsch grows in mata de galeria (gallery forests); neither species was found as host to any other species of Viscaceae in the Distrito Federal (Caires & Proença, unpublished data).
Phoradendron apiciflorum Rizzini is very similar to P. coriaceum Mart.ex Eichler, found in the Brazilian states of Amazonas, Piauí, Alagoas, Bahia, Minas Gerais, Rio de Janeiro, Paraná, and Rio Grande do Sul, and Argentina (Kuijt 2003).Therefore, with additional collections and more detailed studies, P. apiciflorum and P. irwinianum may become synonyms of P. coriaceum.
Selected Material (see Caires & Proença 2005 for complete list of examined material): BRAZIL.