Lophophytum weddellii Hook . f . ( Balanophoraceae ) : first records for the Brazilian flora

Lophophytum weddellii was known to only occur in unflooded forests between 500–1,000 m in Colombia and Peru. These new records for the Brazilian flora expand the geographic distribution of the species, and also show that it occurs near seasonally flooded forests at lower elevations (<500 m). This work presents taxonomic remarks, photographs of living and herbarium specimens of L. weddellii, as well as a geographic distribution map and risk assessment at the regional scale.

Balanophoraceae is among the most representative holoparasite families of the Neotropics (Heide-Jørgensen 2008).Nevertheless, the actual number of species and mainly its geographic distribution remain poorly known in this region.In the last decade, four new species were described (Delprete 2004;Cardoso et al. 2011;Delprete 2014;Cardoso and Braga in press), whereas several others had their geographic distribution significantly extended (Delprete 2004;MacVean and Knapp 2005;Fontana and Popoff 2006;Cardoso 2014a).
Lophophytum Schott & Endl.(subfam.Lopho phytoideae) is a genus with occurrence restricted to South America, which ranges from Colombia to Argentina and comprises four species and one subspecies (Hansen 1980;Kuijt and Hansen 2015).These species are morphologically characterized by the tuber surface covered by irregular lignified slabs, and by the presence of sparse, deltoid, rigid scales.Each tuber usually yields one to five inflorescences that may reach 50 cm in length.The axis of the inflorescence is branched and strobiliform, with deciduous or persistent scale-like bracts that protect each of the branches.In contrast to Lathrophytum and Ombrophytum, the two other genera of the subfamily Lophophytoideae, the branches of Lophophytum are not peltate and their axes are entire covered by unisexual flowers.The staminate flowers have the perianth reduced to 1-2 fleshy segments, where two stamens with more or less developed filaments are inserted.The female flowers are prismatic and have tubular perianths, with two styles with capitellate stigmas.
Lophophytum weddellii Hook.f. was first described more than 150 years ago (Hooker 1856).However, because of the poor representation of this species in herbaria, it can be considered one of the least known species among the Neotropical Balanophoraceae regarding distribution, morphology, and ecology.For instance, Hansen (1980) listed only three specimens in his review of the family to the Neotropics.Until now, L. weddellii was only known to occur in Colombia and Peru at elevations ranging from 500 to 1000 m, frequently associated with Sub-Andean regions, in the upland unflooded forests of the Amazon basin (Hansen 1980;Martínez 1997).This is the only dioecious species of Lophophytum, producing unisexual inflorescences which have persistent bracts that cover the entire inflorescence, even during anthesis of the reproductive structures (Hooker 1856).The staminate branches are multiflorous (> 5 flowers) and the thecae are homomorphic (both of the same size) and inserted at the same height on the connective.The female flowers are ebracteolate and have two labiate extensions at the gynoecium apex.Lophophytum weddellii is morphologically related to L. mirabile Schott & Endl., a widely distributed species in Brazil (Cardoso 2014a), but they can be easily distinguished by the dioecious inflorescences (vs.monoecious in L. mirabile) and by the labiate gynoecium extensions (vs.lacking in L. mirabile) (Hansen 1980).
The first record of L. weddellii for the Brazilian flora was determined during the revision of Balanophoraceae in Brazil (Cardoso 2014b).During this work, the specimen J. Ramos & G. Mota 282 (04.03.1976, INPA 56.954), collected in the state of Acre, northern Brazil (07°41′12.89″S, 073°40′44.87″W), was found deposited in the herbarium of the National Institute for Amazonian Research -INPA, Brazil (Figure 1a and 1b).and Uchiza District at Tochache Province (T.Plowman 5940).The distribution pattern of L. weddellii is related to the "Restricted to Western Amazonia" pattern, which is one of the most representative patterns for the species already inventoried in the Acre State (Daly and Silveira 2008).Figure 3 shows a compilation of the known records of L. weddellii (see additional specimens examined), including those cited by Hansen (1980).
From these two new records for Brazil, the most informative is the one performed by UFAC researchers during the expedition whose voucher was lost.This collection which was made on the margin of the Moa River (07°27ʹ02ʺ S, 073°36ʹ30ʺ W) in the northern portion This specimen has two staminate and one pistillate inflorescence, with all other features that confirm the identity of L. weddellii, according to Hansen (1980).Later, we were told that a second record of this species was made in 1996 by researchers from the Federal University of Acre -UFAC, Brazil.There is only one image of this second record, without voucher, because the material rotted and unfortunately was lost before being deposited in the herbarium (M.Silveira, pers.comm.).In this image, which is one of the few in vivo images of this species, two pistillate inflorescences can be clearly seen, which distinguishes L. weddellii from the other species of the genus (Hansen 1980) (Figure 2).
Both records were made in the Serra do Divisor National Park -SDNP, in the westernmost region of Brazil, in the upper Juruá River basin and near the border with Peru (Figure 3).The SDNP is a difficult area to access that encompasses over 843.000 ha of continuous Amazon Forest.According to Daly and Silveira (2008), (subfam.Scybalioideae), which inhabits flooded areas (várzea forests) and forested wetlands (Igapó forests) throughout the entire basin (Cardoso 2014a(Cardoso , 2014b)).Unfortunately, none of the records provide information on hosts of L. weddellii, which remains unknown for the species.In addition to this new habitat information, the new records contribute to update the First Catalogue of the Flora of Acre (Daly and Silveira 2008), as well as the List of Species of the Brazilian Flora (Cardoso 2014a).Balanophoraceae currently has six genera and 13 species for Brazil, representing approximately 72% of the Neotropical richness, and 30% of all species richness of this family (considering the studies of Delprete 2014; Cardoso and Braga in press; Kuijt and Hansen 2015).
The few records of L. weddellii in Brazil act as sampling artifacts in the Extent of Occurrence (EOO) and Area of Occupancy (AOO) calculation, suggesting a priori a high level of extinction threat.Nevertheless, it can be stated that the real geographic distribution of L. weddellii in the country is still poorly known, and these new records refers to a remote and largely forested region that is contiguous with the actual extensive remaining vegetation of the Acre state (e.g., Shimabukuro et al. 2010).Thus, we cannot accurately recognize the direct threats to the L. weddellii populations.Without more information, it was not possible to infer anything about population data and extension of the geographic distribution of L. weddellii in Brazil.Thus, based on the International Union for Conservation of Nature criteria (IUCN 2012a), and its recommendations (IUCN 2012b, 2014a), we consider L. weddellii as Data Deficient (DD) regionally, and we recommend studies that may support a future regional assessment.Finally, we strongly recommend an international effort to infer the threats and the conservation status of this species in its entire distribution area, since L. weddellii is a naturally rare species which has not been recently collected at many of its previous localities (e.g., Colombia), and also had Check List 11(4): 1678, 14 June 2015 doi: http://dx.doi.org/10.15560/11.4.1678ISSN 1809-127X © 2015 Check List and Authors NOTES ON GEOGRAPHIC DISTRIBUTION Cardoso et al. | Lophophytum weddellii: first records for the Brazilian flora the region of SDNP has many floristic affinities with Andean and Sub-Andean regions.Furthermore, the nearest record of L. weddellii to SDNP is just over 320 km west, across the lowlands of the Ucayali River (Peru), in the Sub-Andean mountainous region of Mariscal Cáceres Province (J.Schunke 5675; T. Plowman & J. Schunke 11639)