Blechnum asplenioides Sw., Kongl

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 : 8-9

2.2. Blechnum asplenioides Sw., Kongl . Vetensk. Acad. Handl. 72, t.3, f.3 (1817). Fig. 3f

Plants terrestrial or rupicolous. Stem erect, scales lanceolate, 2.1–2.6 mm long, pale brown to blackish. Fronds (3.4–) 4.1–10.2 cm long, monomorphic; pinnatisect, petiole 4–9 mm long, paleaceous, adaxially sulcate, with scales at the base similar to those on the stem; rachis adaxially sulcate, with scales at the base and sparse hairs abaxially, scales similar to those on the stem; laminae 3.6–9.7 × 0.8–1.2 cm, linear-lanceolate, gradually narrowed towards the base, forming semicircular lobes; pinnae 5–7 × 4–5 mm, 5–21 pairs, triangular, chartaceous, with sparse diminutive hairs mainly beneath the basal pinnae, which is adnate to the rachis, median and apical pinnae ascending with entire to slightly denticulate margins, apex rounded to subacute; veins free. Sori linear, parallel to the costae; indusia linear, introrse.

Examined material: Alto ParnaÍba , PNNRP, Cachoeira do Sussuapara , 10°09’56’’S, 45°55’38’’W, 422 m, 21.IV.2022, P. H. C. Aguiar et al. 30 ( CCAA, UB); 15.XII.2022, P. H. Castro-Aguiar et al. 168 ( CCAA); P. H. Castro-Aguiar et al. 180 ( CCAA); P. H. Castro-Aguiar et al. 235 ( CCAA) .

Blechnum asplenioides is a South American species, occurring from the region of the Guianas to Argentina ( Dittrich et al. 2015). In Brazil, it occurs in the Amazon, Cerrado, Atlantic Rainforest, and Pampa biomes ( Dittrich et al. 2015; Dittrich & Gasper 2023). This is the first record of this species for the state of Maranhão, where it was collected in the PNNRP on the shore of the Sussuapara waterfall, forming large populations on humid rocks close to waterfalls.

Blechnum asplenioides is characterized by the pinnatisect frond, gradually narrowed in the direction of the base, with the first pinnate pair adnate to the rachis, forming semicircular lobes, and medium pinnae ascending distally.

Blechnum asplenioides resembles B.polypodioides Raddi , which also occurs in the Brazilian Cerrado. The two species have pinnatisect fronds, gradually narrowed in the direction of the base. However, in B. polypodioides the basal pinnae are generally surcurrent with an acute apex, while B. asplenioides presents semicircular basal pinnae with a rounded apex ( Dittrich et al. 2015).

Figures

Figure 3 – a. Anemia buniifolia – habit. b. Anemia oblongifolia - habit. c. Anemia presliana – habit. d-e. Blechnum areolatum – habit. f.Blechnum asplenioides – habit. g. Telmatoblechnum serrulatum – habit. h. Pteridium esculentum var.harpianum – habit. i. Cyclodium meniscioides – habit. (a. P.H. Castro-Aguiar et al. 280; b. P.H. Castro-Aguiar et al. 290; c. P.H. Castro-Aguiar et al. 170; d. P.H.C. Aguiar et al. 21; e. P.H. Castro-Aguiar et al. 171; f. P.H. Castro-Aguiar et al. 168; g. P.H.C. Aguiar et al. 05; h. P.H. Castro-Aguiar et al. 243; i. P.H. Castro-Aguiar et al. 160).