Goniopteris C.Presl, Tent. Pterid.

Smith, Alan R. & Kessler, Michael, 2017, Prodromus of a fern flora for Bolivia. XXX. Thelypteridaceae, Phytotaxa 331 (1), pp. 1-34 : 21-22

Goniopteris C.Presl, Tent. Pterid. 181–183, pl. 7, f. 9–11. 1836.

= Thelypteris Schmidel subg. Goniopteris (C.Presl) Duek, Adansonia , n.s. 11: 720. 1971.

= Thelypteris sect. Goniopteris (C.Presl) C.V.Morton, Amer. Fern J. 53(4): 154. 1963.

Goniopteris is a neotropical genus with 115–120 species ( Salino et al. 2016), and has long been recognized as a natural group ( Christensen 1913, Tryon & Tryon 1982, Smith 1990 a). It is also monophyletic ( Smith & Cranfill 2002, Schuettpelz & Pryer 2007) and has been accorded generic status, e.g., by Brade (1972) and Pichi Sermolli (1977). The presence of furcate or stellate hairs on the blades, axes (stipe, rachial, and costal grooves), blades (including veins and laminar tissue), and/or rhizome apex scales is a useful diagnostic character for Goniopteris ( Salino 2002) , but this character has been secondarily lost in a few species, including three spp. in Peru: G. macrotis (Hook.) Pic. Serm. , G. semihastata (Kunze) Salino & T.E.Almeida (both endemic to Peru; Smith 1992), and G. clypeata (Maxon & C.V.Morton) Salino & T.E.Almeida ( Panama and Peru; Smith 1995a). There are 17 species known from Bolivia, 36 in Brazil ( Salino et al. 2016), and 20 in Peru (Smith 1993). The chromosome base number for the genus is firmly established as x = 36, the same as for the entire Cyclosoroid clade (see Almeida et al. 2016); polyploidy and hybridization are well known in the genus.

Characters of Goniopteris include the free or often united, sometimes areolate venation, the areoles usually in fewer than 3 rows between costa and pinna margins. The sole exception in Bolivia is G. poiteana . Pinnae are usually lobed 1/4 or more of the distance to the costae (except G. poiteana , G. schunkei ). Many species of Goniopteris have small buds in the axils of the distal pinnae that may give rise to new plants when the fronds senesce and decay. By these characters, Goniopteris can usually be readily distinguished from species of Mensicium. Most of the species occur at low and middle elevations. The genus is in need of detailed systematic study.

Characters used to distinguish Bolivian species of Goniopteris include: rhizome habit (creeping vs. suberect or erect); blade dissection (pinnatifid vs. 1-pinnate); blade apex configuration (whether conform or pinnatifid and gradually reduced); pinna lobing (entire vs. shallowly lobed vs. deeply pinnatifid); venation (connivent at sinuses or anastomosing below sinuses); blade indument (hairs simple, forked, or stellate, as well as density and location of hairs); presence or absence of rachis buds, also whether these subapical or proximal); and presence or absence of indusia.