Blechnum laevigatum Cavanilles (1802: 263)

Dittrich, Vinícius Antonio De Oliveira, Salino, Alexandre & Monteiro, Reinaldo, 2015, The Blechnum occidentale (Blechnaceae, Polypodiopsida) species group in southern and southeastern Brazil, Phytotaxa 231 (3), pp. 201-229 : 214-215

7. Blechnum laevigatum Cavanilles (1802: 263) . Fig. 4A–C

Type:— URUGUAY or ARGENTINA. Probably Montevideo or Buenos Aires, without date, L. Née s.n. (holotype MA 213336).

Blechnum distans Presl (1836: 103) . Blechnum occidentale var. distans (C. Presl) Baker (1870: 425) . Type:— BRAZIL: without date, Sellow s.n. (holotype B200030973, isotype NY00149757).

Blechnum juergensii Rosenstock (1905: 59) . Type:— BRAZIL. Rio Grande do Sul: Cerro (Serra) de Agre (Acre), 150 m, January 1904, C. Jürgens 162 [Rosenst. filic. austrobr. exsicc. 262] (holotype B200031512, isotypes BM000769829, GH00020659, K000633406, R, RB, S-R-674, S10-30453, R674, UC441941, US 00067426).

Plants terrestrial or epipetric; rhizomes erect to decumbent, stoloniferous, the scales narrowly triangular, brown, shiny, margin entire, 1.6 × 0.6 mm; fronds monomorphic, 6.9–18.4 cm long.; stipes 1.7–6.8 cm long, 0.4–0.9 mm diam., paleaceous, with multicellular, catenate, hyaline hairs up to 0.5 mm long and scarce scales lighter than those of the stem, lanceolate, subclathrate or not, whitish or tan, concolorous, 1.4–1.8 × 0.4–0.5 mm above base, margin entire; blade 4.3–10.4 × 1.6–4.6 cm, membranaceous, hairy, lanceolate or rarely elliptical, at base pinnate, little reduced or commonly with 2 or 3 pairs of reduced pinnae, pinnatissect towards the gradually reduced apex; rachis hairy on both surfaces; pinnae 15–19 pairs, 0.9–2.4 × 0.3–0.8 cm, fully adnate to the rachis, except the first and sometimes the second pair that are excavate, the basal ones reflexed, the others patent or a few apical ones slightly ascending, with obtuse, acute or mucronate apices, margins entire, hairy on both surfaces, on and between veins and on margins, the hairs similar to those of the stipes; veins free, 1–2-bifurcate, with clavate ends on or just before the margin.

Distribution and habitat: — Brazil (Minas Gerais, Paraná, Santa Catarina, and Rio Grande do Sul), Uruguay and Argentina. Murillo (1968) cites the species for Mato Grosso do Sul. Observed specimens inhabit mainly humid and/or dark localities inside forests or on sandstone cliffs. In the study area, it occurs between 290 and 1650 m. A relatively common species in southern Brazil, it is not locally endangered.

Comments: — Blechnum laevigatum is a species close to Blechnum occidentale and Blechnum austrobrasilianum . It differs from the former by the blade texture (membranaceous in B. laevigatum , papyraceous to subcoriaceous in B. occidentale ), by the dense pubescense in B. laevigatum in almost all parts of the plant (in B. occidentale , when hairs are present, these are limited to the rachis) and by the proximal pair of pinnae, with the acroscopic surface totally free from the rachis in B. occidentale and partially to fully adnate in B. laevigatum . It differs from B. austrobrasilianum by the general pubescense (in B. austrobrasilianum the hairs, when present, occur on the rachis, rarely on the veins, never on the margin of the leaf blade or between veins). The plant illustrated in Sehnem (1968, p. 18, t.6, f.1) corresponds with B. laevigatum .

Selected specimens examined: — BRAZIL. Minas Gerais: Caldas, distrito de Pocinhos do Rio Verde, Pedra Branca , 21°58’40.4”S, 46°22’16.4”W, 1650 m, 15 July 2007, A. Salino et al. 12606 ( BHCB). Paraná: Lapa , Serrinha , 03 November 1946, O. Curial 97 ( MBM) ; Ponta Grossa, Vila Velha , 900 m, 04 October 1963, G.G. Hatschbach 10231 (B, MBM, PACA) ; Porto Amazonas, Fazenda São Roque, 03 February 1975, R. Kummrow 1077 ( MBM, PACA). Santa Catarina: Sombrio, Furnas do Sombrio , 28 January 1964, O.R. Camargo 3962 ( PACA). Rio Grande do Sul: Pelotas, próximo ao Capão do Leão , 03 June 1959, G.L. Brauner 107 ( PACA) ; Rio Pardo, Cerro ( Serra ) de Agre (Acre), 1906, C. Jürgens s.n. ( HBR 26517 ) ; Sapucaia do Sul, Morro Sapucaia , 290 m, 29 June 1986, I. Fernandes 153 ( SJRP) .

Figures

FIGURE 4.A–C.Blechnum laevigatum.A. Habit. B. Lamina apex showing indument. C. Rhizome scale.D–F.Blechnum lanceola: D. Habit. E. Part of a pinna showing venation and sori. F. Rhizome scale. (A–C from L. Krieger s.n., CES 11193; D–F from A.C. Brade 3365 (CESJ).