Adiantum deflectens Mart.,

Castro-Aguiar, Pedro Henrique, Fernandes, Rozijane Santos & Zappi, Daniela Cristina, 2025, Ferns of the Parque Nacional das Nascentes do Rio Parnaíba Brazilian Cerrado, Rodriguesia (e 00612024) 76, pp. 1-24 : 16

12.1. Adiantum deflectens Mart., Icon. Pl. Crypt. 94 (1834).

Plants terrestrial or rupicolous. Stem erect, with linear-lanceolate scales, 1.4–2 mm long, dark brown with pale brown margins. Fronds 10.5–18.5 cm long, monomorphic, 1-pinnate, erect; petiole 4–9.5 cm long, dark brown to black, glabrous, only at the base with scales similar to those on the stem; rachis cylindrical, dark brown to black, glabrous; laminae 4–13.5 × 2.2–3.5 cm, linear-lanceolate; pinnae 0.8–1.1 × 1.1–1.6 cm, 4–14 pairs, flabellate, slightly chartaceous, glabrous on both sides, margins denticulate, base obtuse, apex rounded; veins free. Sori oblong-linear along the acroscopic margin; pseudo-indusia glabrous.

Examined material: MARANHÃO: Alto ParnaÍba, Povoado Porto Alegre , 09°51’50’’S, 46°06’03’’W 385 m, 18.III.2023, P. H. Castro-Aguiar et al. 296 ( CCAA, UB). PIAUÍ: Barreiras do PiauÍ, Rio UruçuÍ Vermelho , 09°57’14’’S, 45°34’15’’W, 396 m, 20.IV.2022, P. H. C. Aguiar et al. 18 ( CCAA).

Adiantum deflectens is a Neotropical species, occurring from Mexico to Argentina (Kessler et al. 2017). In Brazil, it occurs in the Amazon, Cerrado, and Atlantic Rainforest biomes ( Prado & Hirai 2023a). In the study area it was observed growing on arenitic cliffs, roadsides, and in shaded areas within the forest.

This species is characterized by the1-pinnate lamina, flabellate pinnae articulated to the rachis, with denticulate margins, and pseudo indusia oblong-linear, glabrous.