Sticherus decurrens (Raddi) J.Gonzales

Gonzales, Jasivia & Kessler, Michael, 2011, A synopsis of the Neotropical species of Sticherus (Gleicheniaceae), with descriptions of nine new species, Phytotaxa 31, pp. 1-54 : 23

Sticherus decurrens (Raddi) J.Gonzales , comb. nov.

Mertensia decurrens Raddi (1825: 73 t). Type: — BRAZIL. Rio de Janeiro. Raddi s.n. (holotype not located, perhaps at FI, isotype P!).

Gleichenia mathewsii Hooker (1844: 9) . Mertensia mathewsii (Hook.) Fée (1866: 122) . Sticherus mathewsii (Hook.) Nakai (1950: 22) . Type: — PERU. Chachapoyas, 1844?, Mathews 1092 pro parte (holotype K!, isotype US!).

Gleichenia tuberculata Mett. ex Kuhn (1869: 166) . Sticherus tuberculatus (Mett. ex Kuhn) Nakai (1950: 30) . Type: — PERU. Puno: Tatanara, Lechler 2572 (holotype B!, isotype B!).

Mertensia trifurcans Fée (1869 : 1.201 t. 74, f. 1). Type: — BRAZIL. Rio de Janeiro: Tijuca, Glaziou 1697 (holotype K!, isotype US!) .

Distribution and ecology: —Andes of Ecuador, Peru, and Bolivia; southeastern Brazil. Very common in Brazil and somewhat less so in Bolivia, but is quite rare elsewhere in its range. Grows mainly in open, disturbed habitats such as on landslides and along roadcuts, but is also found in secondary and disturbed forests. At 300–2750 m in the Andes and 120–1500 m in Brazil.

Notes: —As defined here, S. decurrens is a rather variable species. Whereas many specimens are typical of the species, other collections may be hybrids with S. bifidus , S. ferrugineus , S. nigropaleaceus , and possibly others. The problem in distinguishing “true” S. decurrens from such hybrids is that the characters defining S. decurrens are intermediate between those of the species cited above. It is conceivable that S. decurrens itself is of hybrid origin, but the presence of large, reproductive populations in the field leave no doubt that today it is a distinct, viable species. The variability of this species and the similarity of the putative hybrids have prompted the description of several species that are here considered to be synonymous with S. decurrens ( S. mathewsii , S. trifurcans , and possibly Gleichenia immersa ; see under doubtful names). Some of these names may actually apply to hybrids rather than to S. decurrens . Cytological and molecular studies are needed to clarify these problems.