Lindsaea Dryand. ex Sm., Mem. Acad. Roy. Sci.

Smith, Alan R. & Kessler, Michael, 2017, Prodromus of a fern flora for Bolivia. XXV. Lindsaeaceae, Phytotaxa 332 (3), pp. 290-294 : 291

Lindsaea Dryand. ex Sm., Mem. Acad. Roy. Sci. (Turin) 5: 413, pl. 9, f. 4. 1793.

= Ormoloma Maxon, Proc. Biol. Soc. Wash. 46: 143. 1933.

Lindsaea has sulcate and often strongly angled petioles adaxially (± terete in a few species), usually dimidiate (unequal-sided) pinnae or pinnules, submarginal sori, and true indusia opening towards the segment margin. The blades are generally herbaceous to chartaceous or occasionally subcoriaceous. The species superficially resemble some species of Adiantum L. ( Pteridaceae ), which have similarly shaped pinnae/pinnules, but Adiantum has terete petioles and rachises, the indusia are formed by the reflexed pinna/pinnule margins (i.e., opening inwardly or introrse), and the sporangia are borne on the indusia. Lindsaea and six other genera ( Nesolindsaea Lehtonen & Christenh. , Odontosoria , Osmolindsaea (K.U.Kramer) Lehtonen & Christenh. , Sphenomeris , Tapeinidium (C.Presl) C.Chr. , Xyropteris K.U.Kramer ) make up the family, with Lindsaea by far the largest genus. The lindsaeoid genera have all been placed historically in Dennstaedtiaceae , but recent phylogenetic research shows that they are best placed in a separate family ( Pryer et al. 2004, Korall et al. 2006, Schuettpelz et al. 2006). Lindsaea is pantropical with about 150 species, with about 50 neotropical species concentrated in southeastern Venezuela and the Guianas. Species of Lindsaea are typically found in primary, relatively undisturbed rain forests, usually at lower and middle elevations, often on nutrient-poor, sandy soils or on ridges with leached soils, at low to middle elevations, in wet forests ( Young & León 1989, Lehtonen & Tuomisto 2007). As an adaptation to nutrient-poor soils, they typically have mycorrhizal associations ( Kessler et al. 2014, Lehnert et al. 2016). Bolivia has nine species, relatively few compared to the Guianas and Venezuela (ca. 35 spp.), and most of these are relatively widespread in South America, extending into the Antilles, Mesoamerica, and southern Mexico. The Peruvian species have been treated by Tryon (1964) and Tryon & Stolze (1989). The species in southern Mexico and Mesoamerica were recently reviewed by Rojas-Alvarado & Tejero-Díez (2017), who described three new species, elevated a variety of L. quadrangularis to species rank, and ascribed several predominantly South American species also to Mesoamerica and Mexico. The paleotropical species of Lindsaea are diverse and number nearly 150 species; Kramer (1971) treated those from the Flora Malesiana region and has also published on those from elsewhere in the Old World. Most of the neotropical species, and all of the ones in Bolivia have been shown by Lehtonen et al. (2010) to comprise a well supported clade (their Clade XIII).