Melpomene A.R.Sm. & R.C.Moran, Novon

Smith, Alan R., Kessler, Michael, León, Blanca, Almeida, Thaís Elias, Jiménez-Pérez, Iván & Lehnert, Marcus, 2018, Prodromus of a fern flora for Bolivia. XL. Polypodiaceae, Phytotaxa 354 (1), pp. 448-450 : 448-450

Melpomene A.R.Sm. & R.C.Moran, Novon 2(4): 426. 1992.

Melpomene was first defined by Smith & Moran (1992), and at that time it contained 20 species. Species are largely epiphytic at elevations below timberline, but often terrestrial or epilithic in paramos at high elevations. The genus is distinguished by having short- to long-creeping rhizomes; strongly clathrate rhizome scales with a cordate base and entire margins, with some species having a cluster of glandular cells at the tips; absence of phyllopodia; pinnatifid or pinnatisect, often thick-textured blades; pronounced hydathodes at the vein tips adaxially; generally setose petioles and rachises, the setae reddish brown; free, simple veins; and round, superficial sori. Since its original description, a few species have been reassigned to other genera, others subsumed, and still others newly described. In the latest revision ( Lehnert 2013), Melpomene is monophyletic and contains 29 species in the Neotropics and Africa/ Madagascar; four of these comprise two or more varieties, including four of the most widespread species in the genus ( M. flabelliformis , M. moniliformis , M. pilosissima , M. xiphopteroides ), three of which occur in Bolivia. The genus is centered in the Andes, at middle to high elevations, with 16 species in Bolivia; five additional species have ranges that extend as far south as Peru, and these could eventually be found in Bolivia: M. pilosissima (M.Martens & Galeotti) A.R.Sm. & R.C.Moran , M. pseudonutans (Christ & Rosenst.) A.R.Sm. & R.C.Moran , M. vernicosa (Copel.) A.R.Sm. & R.C.Moran , M. wolfii (Hieron.) A.R.Sm. & R.C.Moran , and M. youngii (Stolze) B.León & A.R.Sm.

Phylogenetically, Melpomene appears to be sister to Lellingeria + Stenogrammitis , and this combined clade sister to Mycopteris ( Lehnert et al. 2009, Lehnert 2013). Many of the species commonly occur above 3000 m and Melpomene appears to have radiated with the uplift of the Andes, with the most derived species occupying the highest elevations, in paramo habitats, up to 4700 m ( M. peruviana ). In fact, M. peruviana is the highest-growing epiphytic vascular plant species worldwide, reaching 4520 m in the Peruvian Andes ( Sylvester et al. 2014).

Melpomene is characterized by a strong fragrance that remains evident even on herbarium specimens over 100 years old, and that has been described as ‘decidedly sweet’ ( Mickel & Beitel 1988) and ‘sweet spicy’, as well as ‘almost overpowering to some individuals’ ( Smith & Moran 1992). Other descriptions of the smell compare it with pine needles ( Tryon & Stolze 1993) and rhubarb tincture ( Christ 1897). Because of its pleasant smell, Melpomene melanosticta is used by native tribes in Amazonia to manufacture necklaces ( Macía 2004). The scent components have been studied by Kessler et al. (2015) who proposed that they may play a role in herbivore defense, although with a different scent bouquet than is typical in angiosperms for the same purpose ( Schiestl 2010, Kessler et al. 2015).

Smith & Moran (1995) treated the species from Mesoamerica, Mickel & Smith (2004) those from Mexico, and Labiak & Prado (2005c) treated the Brazilian species.