Cyathea cylindrica S.Maciel & Lehnert, 2017

Maciel, Sebastião, Lehnert, Marcus, Hirai, Regina Y. & Prado, Jefferson, 2017, Three new species of the Cyathea “ Hymenophyllopsis ” clade (Cyatheaceae) from Venezuela and Brazil, Phytotaxa 329 (2), pp. 159-166 : 162

Cyathea cylindrica S.Maciel & Lehnert , sp. nov. Figs. 1E–I , 3 .

This new species had usually been misinterpreted as Cyathea dejecta (Baker) Christenhusz (2009: 39) (≡ Hymenophyllopsis dejecta (Baker) Goebel (1929: 3) and C. hymenophylloides (L.D.Gómez) Christenhusz (2009: 39) (≡ H. hymenophylloides Gómez (1973: 103 f. 1, 2)). However, C. dejecta differs in having concolorous rhizome scales (vs. bicolorous rhizome scales in C. cylindrica ) and rachises with scales (vs. scales absent in C. cylindrica ). Cyathea hymenophylloides has concolorous rhizome scales, with the cells of the scale body exhibiting thick walls, and entire margins or rarely with some small setiform projections towards the apex (vs. bicolorous scales in C. cylindrica , with the cells in the center of the scale body with thick walls, and short teeth at the base and few, small setiform projections towards the apex), and petioles and rachises with scattered clavate hairs (vs. catenate and clavate hairs in C. cylindrica ).

Type:— VENEZUELA. Amazonas: Atabapo. Plateau of Cerro de Marahuaca above Salto Los Monos on tributary of headwaters of Río Iguapo , 03º37’N, 65º23’W, 2555 m, 26 February 1985, R. L. Liesner 17989 (holotype US barcode US 00785475!; isotypes MO, not seen, VEN, not seen) .

Plants rupicolous. Rhizomes ascending to erect, 1.2–2.5 mm in diam. (3.7–5.4 mm in diam., including roots, petioles and scales), with scales, surface of the rhizomes usually visible between the scales; scales lanceolate, 1.5–2.2 × 0.2–0.3 mm, slightly shiny, slightly contorted, bases truncate, the cells in the center with thick walls, bicolorous, castaneous with a central brown stripe, margins light brown with short teeth at base and few, small setiform projections towards apex, apices attenuate, ending in a single cell, castaneous to brown. Fronds 2.3–10.0 × 0.6–2.4 cm, caespitose, erect; petioles 0.2–0.7 mm in diam., 0.6–4.9 cm long, brown to atropurpureous, cylindrical, sparsely scaly at base, scales similar to those of the rhizomes but more contorted, narrower and shiny, distally with sparse catenate and clavate hairs; laminae 3- or 4-pinnate at base and 3-pinnate distally, 7–12 pairs of lateral pinnae, lanceolate, 1.7–5.1 × 0.6–2.4 cm; rachises slightly rounded on both sides or slightly grooved adaxially, sparsely pubescent on both surfaces with two kinds of hairs, catenate and clavate; pinnae 2- or 3-pinnate proximally and 2-pinnate distally, 3 or 4 pairs of pinnules, opposite or alternate basally and alternate distally, patent proximally and patent to ascending distally, 0.3–0.8 cm apart, approximate to imbricate, terete or sometimes flattened, apices patent or pendent, glabrous or with scattered clavate hairs on both surfaces; proximal pinnules pair pinnate or slightly digitate, alternate, margins entire, cylindrical to sometimes flattened distally; sterile pinnules 0.2–0.5 mm wide, apices round; fertile pinnules 0.3–0.4 mm wide, apices ending in one sorus. Sori 1–6 per pinnae, projecting or immersed in the laminar tissue, laminar tissue below indusia not constricted, sori occurring always at the acroscopic and basiscopic base of the pinnules; indusia mostly bivalvate, adaxial valve ca. 0.9 mm long, margin subentire to triangular-lobed, abaxial valve ca. 0.5 mm long, margin subentire to repand, rarely appearing cyatheoid if valves very short, then cup ca. 0.5 mm long, margins subentire to triangular-lobed; spores 32 per sporangium, trilete, yellowish.

Distribution and ecology: — This species occurs only at high elevations (1850–2555 m) in Venezuela and Brazil. It grows in erect tufts, on ledges of weathered sandstone outcrops, mostly in the crevice of rocks near swampy savannahs, on moist shaded canyon walls and along streams.

Etymology: —The specific epithet cylindrica refers to the terete pinnae and pinnules.

Additional specimens examined (paratypes): — VENEZUELA. Bolívar: Piar. Macizo del Chimantá, pequeñas altiplanicies en la base septentrional de los farallones superiores del Amurí-tepui (sector W del Acopán-tepui), 05º10’N, 62º07’W, 1850 m, 2–5 February 1983, J. A. Steyermark et al. 128605 ( NY) ; idem, id., sector SE, altiplanicie levemente inclinada hacia el SSE ubicada en la sección centro-suroriental del Churí-tepui , 05º15’N, 61º58’W, 1850 m, 10–12 February 1984, O. Huber & M. Colella 8988 ( NY) . Amazonas: Venezuelan-Brazilian Frontier, Cerro de la Neblina, Planicie de Zuloaga , Río Titirico , [01º04’N, 66º09’W], 2300 m, 10–15 October 1983, J. A. Steyermark 103893 ( NY) .— BRAZIL. Amazonas: Santa Isabel do Rio Negro. Parque Nacional do Pico da Neblina, trilha para a Cachoeira do Anta, alto da Serra da Neblina , acampamento do Marco 5 da fronteira Brasil com a Venezuela, 00º00’N, 65º00’W, 2343 m, 31 December 2004, F. A. Carvalho et al. 372 ( INPA) .

Notes: — Cyathea cylindrica is readily recognized by its terete frond axes and segments without expanded laminar tissue. It also has bicolorous rhizomes scales, with few, small, setiform marginal, mainly distal, projections. There are two kinds of hairs (catenate and clavate) scattered on rachises, and only clavate hairs on the pinnae.

Figures

FIGURE 1. A–D. Cyathea alsophiloides: A. Habit. B. Rhizome scale. C. Detail of the pinna adaxially.D. Detail of the indusia (Steyermark et al. 128825-A, US). E–I. Cyathea cylindrica: E. Habit. F. Rhizome scale. G. Detail of the pinna adaxially. H. Detail of the hairs catenate and clavate on the rachises. I. Detail of the indusia (Liesner 17989, US).

FIGURE 3. Distribution of Cyathea alsophiloides (stars), C. cylindrica (dot), and C. lellingeriana (triangle) in Venezuela and Brazil.