Trichomanes pinnatum Hedw.,

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 : 13-14

9.2. Trichomanes pinnatum Hedw., Fil. Gen. Sp. t.4, f.1 (1799). Fig. 4e

Plants terrestrial or rupicolous. Stem erect to short-creeping, with blackish hairs. Fronds 8.2–28.2 cm long, subdimorphic, 1-pinnate, with fertile fronds longer than sterile ones; petiole (1.6–) 3.2–15.2 cm long, dark-brown to black, with sparse dark-brown hairs; laminae 5–13 × 5.3–15.5 cm, oblong to ovate; rachis alate, with sparse to moderate dark-brown hairs adaxially, rooting apex on sterile laminae; pinnae 2.3–9.9 × 0.8–1.3 cm, 4–15 pairs, linear to oblong, membranaceous, sessile to adnate to the rachis, with sparse hairs mainly on the veins, margin dentate, apex rounded to acute, not imbricate; veins free, ending in a main collecting vein at the margin, with abundant false veins parallel to the true veins. Sori on the margin of the pinnae; indusia tubular, sessile to short pedicellate.

Examined material: MARANHÃO: Alto ParnaÍba , PNNRP, Cachoeira do Sussuapara , 10°09’56’’S, 45°55’38’’W, 21.IV.2022, P. H. C. Aguiar et al. 26 ( CCAA, UB); P. H. C. Aguiar et al. 37 ( CCAA); P. H. C. Aguiar et al. 49 ( CCAA); 10°09’56’’S, 45°55’39’’W, 15.XII.2023, P. H. Castro-Aguiar et al. 177 ( CCAA); P. H. Castro-Aguiar et al. 237 ( CCAA); 10°10’09’’S, 45°55’27’’W, 21.IV.2022, P. H. C. Aguiar et al. 49 ( CCAA); trilha em direção a Cachoeira do Sussuapara , 10°09’56’’S, 45°55’39’’W, 15.XII.2022, P. H. Castro-Aguiar et al. 173 ( CCAA). PIAUÍ, Barreiras do PiauÍ, PNNRP, Cachoeira do Pintado , 10°11’26’’S, 45°51’08’’W, 436 m, 13.XII.2022, P. H. Castro-Aguiar et al.60 ( CCAA); P. H. Castro-Aguiar et al.62 ( CCAA); P. H. Castro-Aguiar et al.79 ( CCAA); Cachoeira do Urubu , 10°11’45’’S, 45°47’48’’W, 14.XII.2022, P. H. Castro-Aguiar et al. 99 ( CCAA); Cachoeira Várzea Grande, 10°12’11’’S, 45°47’58’’W, 474 m, 14.XII.2022, P. H. Castro-Aguiar et al. 114 ( CCAA, UB); P. H. Castro-Aguiar et al. 115 ( CCAA, UB) .

Trichomanes pinnatum is a Neotropical species, occurring from Mexico to South America, and in the Caribbean region (Kessler & Smith 2017). In Brazil, it occurs in the Amazon, Cerrado, and Atlantic Rainforest biomes ( Gonzatti & Windisch 2023). In the study area, it was recorded growing close to waterfalls, on river margins and streams inside the gallery forest.

Trichomanes pinnatum is characterized by subdimorphic fronds, with the fertile laminae frequently a little larger and with petioles longer than the sterile ones, pedicellate indusia, and abundant false veins perpendicular to the true veins.

In the examined specimens from the study area, the sterile laminae can present the apex conform or continuous, with the rachis proliferating distally.

Figures

Figure 4 – a.Elaphoglossum scalpellum – habit.b-c.Dicranopteris flexuosa – b. habit; c. sori on the abaxial surface.d.Trichomanes pilosum – habit. e. Trichomanes pinnatum – habit. f. Lindsaea divaricata – habit. g. Lindsaea lancea – habit. h-i. Metaxya parkeri – h. babit; i. sori on the abaxial surface. (a. P.H. Castro-Aguiar et al. 172; b-c. P.H. Castro-Aguiar et al. 67; d. P.H. Castro-Aguiar et al. 238; e. P.H. Castro-Aguiar et al. 173; f. P.H.C. Aguiar et al. 8; g. P.H.C. Aguiar et al. 28; h-i. P.H. Castro-Aguiar et al. 165).