Nota Científica On the occurrence of Lejeunea pulverulenta ( Marchantiophyta , Lejeuneaceae ) in Brazil

Lejeunea pulverulenta is recorded for the first time to the Northeast of Brazil. The specimen was collected in Serra Bonita, Municipality of Camacan, southern Bahia, Brazil. Herein the species is described and illustrated.

Lejeunea Lib. is the largest genus of the family Lejeuneaceae, with more than 300 recognized species (Heinrichs et al. 2013), and is distributed worldwide.In Brazil, the genus is represented by 40 species (Costa & Peralta 2015); however, a new species, Lejeunea combuensis O.S. Moura, Ilk.-Borg.& M.E.Reiner, was recently described for the state of Pará (Moura et al. 2012).Ilkiu-Borges (2000) and Bastos (2004) published the first treatments of the family Lejeuneaceae for the states of Pará and Bahia, respectively, while Bastos & Yano (2009) performed the first treatment of the genus Lejeunea for the state of Bahia, describing 21 species.
Lejeunea is a complex genus, and the identification of most of its species depends on characteristics of the perianth.However, the genus can be recognized by the combination of the following characters: (a) Lejeunea-type vegetative branches; (b) innovation with lejeunoid sequence; (c) first tooth of lobule prominent, with hyaline papilla located at its proximal base; (d) Jungermannia-type or Massula-type oil bodies; (e) generally bifid, rarely entire underleaves; and (f) perianth 5-keeled or smooth.According to Heinrichs et al. (2013), the center of diversity for the genus is the humid tropics, but it also inhabits temperate zones.
During studies that resulted from the project "Briófitas do corredor central da floresta atlântica brasileira: de onde partimos, para onde vamos?" ("Bryophytes of the central corridor of the Brazilian Atlantic Forest: where do we begin, where are we going?") coordinated by the last author, Lejeunea pulverulenta (Gottsche ex Steph.)E. Reiner, a rare species cited for Brazil but without locality and known to occur in Guadeloupe, Ecuador and Guiana (Reiner-Drehwald 2005), was encountered.Thus, the distribution of this species in Brazil is not known.Thus, the objective of this work is to report the occurrence of this species in state of Bahia, Northeastern Brazil.
Lejeunea pulverulenta is characterized by leaf lobe with rounded apex, and sharp border of 5−6 rows of smaller marginal cells perpendicular to the larger, central cells, cells with trigones and strongly papillose surface, underleaves imbricate with auriculate bases and acute lobes, perianth with keels irregularly ornamented with teeth and small cilia.Lejeunea pulverulenta is morphologically closely related to Lejeunea controversa Gottsche, but differing by following characters: (a) leaf lobe apex entire (occasionally with few teeth on dorsal margin near the apex in L. controversa); (b) leaf lobe apex widely rounded (subacute to apiculate in L. controversa); (c) underleaf base auriculate (rounded in L. controversa) (fide Reiner-Drehwald 2005).
Lejeunea pulverulenta is known from Guadeloupe, Ecuador and Guiana.It was cited for Brazil but without locality.The specimen was found growing on the trunk of a live tree.
Lejeunea pulverulenta was initially described as Taxilejeunea pulverulenta Gottsche ex Steph., and subsequently transferred to the genus Lejeunea by Reiner-Drehwald (2005).According to Reiner-Drehwald (2005), Taxilejeunea pulverulenta was described based on plants from Guadeloupe and Brazil, however, this author does not indicate the geographic distribution of any locality of occurrence of this species in Brazil, and only refers to Monte Roraima (Mount Roraima), but in Guiana.Stephani (1914) also reported the occurrence of L. pulverulenta in Brazil but without indicating the locality (Brasilia orientalis).Thus, here we report for the first time a precise locality of occurrence of this species in Brazil.However, this restricted distribution in Brazil may be due to insufficient collection or to the difficult of identifying the species.Examination of several herbarium collections or the implementation of greater collection effort may reveal a wider distribution of the L. pulverulenta in Brazil, or even in the neotropics.