Sticherus longipinnatus (Hooker) Ching (1940: 238)

Lima, Lucas Vieira & Salino, Alexandre, 2018, The fern family Gleicheniaceae (Polypodiopsida) in Brazil, Phytotaxa 358 (3), pp. 199-234 : 221

3.6. Sticherus longipinnatus (Hooker) Ching (1940: 238) . Figs. 7O–S , 8B , 9A .

Gleichenia longipinnata Hooker (1844: 9) . Mertensia longipinnata (Hook.) Klotzsch (1844: 537) . Dicranopteris longipinnata (Hook.) Maxon (1922: 48) . Type:— SURINAM. Hostmann 238 (lectotype designated here, K [K000589334]!, isolectotypes B! [B 20 0139886], BM [BM000585933; BM000585934] K [K000589335]!).

Plants terrestrial. Rhizomes 1.8–4.28 mm thick, with scales dark-brown, rigid, triangular, with apex acuminate, base truncate, margins setose. Fronds scrambling, 1–2-forked, petiole 2.71–2.82 mm thick, ultimate branches 27–98 × 3.4–6.2 cm, elliptic, apex pinnatifid, base slightly reduced, abaxial surface dense to moderately scaly on the rachis, scales dark-brown to reddish, linear, apex acuminate, base truncate, margins setose, adaxial surface densely covered by dark-brown to reddish filiform scales on the rachis, segments linear 2.7–3.2 × 0.24–0.30 cm, margins plane to slightly revolute, abaxial surface with filiform scales on the secondary veins, midrib with dark-brown to reddish, hastate, filiform and triangular scales. Buds with reddish, linear scales, with apex filiform, base truncate, margins setose, pseudoestipule present. Veins 1-forked. Sori medial to supramedial, without paraphyses.

Distribution and habitat: — Brazil (Acre and Pará), Ecuador, Peru, and Suriname. In Brazil, this species occurs along forest edge in the Amazonian domain, at 500– 600 m.

Notes: — Sticherus longipinnatus is easily recognized by the anchor-shaped scales on the abaxial rachis surfaces and segment midribs, and very long ultimate branches with segments very close to each other. It appears to be a rare species due to the few herbarium records. In Brazil, there are only two records with a collection gap of 37 years. Despite the paucity of collection efforts in the occurrence area of the species, it should be considered that this species might be threatened.

In the original description, Hooker cited the collection Hostmann 238 from Suriname as type material. We found five exsiccatae of this collection, two in K, one in BM, one in FI, and one in B. Tryon & Stolze (1989) made a nonintentional lectotypification by indicating the K material as holotype. However, there are two original specimens at K, and here we proceed with a second step lectotypification. We chose as lectotype the most complete specimen with the label of Hostmann, as the other specimen has a handwritten label of the collection data. The FI specimen has a transcript label with only the original numeration, the B specimen also has a transcript label, and the BM specimens both have transcript labels.

Selected specimens examined: — BRAZIL. Acre: Cruzeiro do Sul, Serra da Moa, entre os rios Jurua e Moa, 30 April 1971, Prance 12681 (K, NY). Pará: Oriximiná, Estação ecológica do Grã Pará, Trilha T2 entre a parcela 1 e o acampamento, 01º96’32.1”N 58º41’29.2”W, 600 m, 27 August 2008, Maciel 780 (BHCB).

Figures

FIGURE 7. A–E. Sticherus nigropaleaceus (Lima 20, CESJ). A. Detail of the abaxial segment surface. B. Rhizome scale. C. Bud scale. D. Rachis scale. E–I. S. paulistanus E. Detail of the abaxial segment surface. F. Rhizome scale. G. Bud scale. H. Rachis scale. I. Arachnoid scale of the abaxial side of the laminae. J–N. S. lanuginosus (Novelino s.n., CESJ 29978). J. Detail of the abaxial segment surface. K. Rhizome scale. L. Bud scale. M. Rachis scale. N. Arachnoid scale of the abaxial side of the laminae. O–R. S. longipinnatus (Maciel 780, BHCB). O. Detail of the abaxial segment surface. P. Rhizome scale. Q. Bud scale. R. Rachis scale. S. Anchor-shaped scale of the abaxial rachis surface.

FIGURE 8. Habit. A. Sticherus lanuginosus. B. S. longipinnatus. C. S. nigropaleaceus. D. S. paulistanus.

FIGURE 9. Distribution of five taxa of Sticherus in Brazil.A. Sticherus longipinnatus, S. paulistanus. B. S. nigropaleaceus and S. salinoi. C. S. pruinosus and S. remotus. D. S. squamosus.