Rumohra glandulosissima (Dryopteridaceae) a New Species from the Atlantic Rainforest, and Revision of the Species Occurring in Brazil

Abstract—

Rumohra is represented by three species in Brazil. Two of them, R. glandulosissima and R. quadrangularis, are endemic and restricted to upper elevation openings in the Atlantic Rainforest from Rio de Janeiro and São Paulo States, and Rio de Janeiro and Rio Grande do Sul States, respectively. The third species, R. adiantiformis, is widespread. The new species here described, R. glandulosissima, is easily recognized by having densely glandular indument on all parts of the leaf. These glands are formed by two kinds of hairs. The first type are erect, capitate, ca. 0.1 mm long, hyaline, composed of three cells, with the basal and apical cells pale yellow, the central cell clear, and the apical cell slightly enlarged compared to the other cells. It does not produce any apparent exudate. The second type of glandular hair is sessile (dot-like), apparently formed by a single cell, ca. 0.1 mm wide, and less than 0.1 mm tall, and surrounded by a shiny reddish exudate. All three species are described, illustrated and distinguished by a key. These results are important for the conservation of rare plants in Brazil where there is a cottage industry of extracting leaves of Rumohra from wild populations for sale as floral greens.