Cyathea oblonga Domin (Domin 1929
Creators: name: Lehnert, Marcus
name: Tejedor, Adrian
name: Kessler, Michael
name: Rodríguez Duque, Wilson D.
name: Gallego, Luis Fernando Giraldo
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Polypodiopsida
Cyatheales
Cyatheaceae
Cyathea
Cyathea oblonga

description: Cyathea oblonga (Klotzsch) Domin
Figs 7–8
Cyathea oblonga (Klotzsch) Domin (Domin 1929a: 263). – Alsophila oblonga Klotzsch (Klotzsch 1844: 540). – Trichipteris oblonga (Klotzsch) R.M.Tryon (Tryon 1970: 46).
– Type: GUYANA • R. Schomburgk 1125; lectotype: K [K000589887]!, designated by Barrington 1978; isolectotypes: B [B 20 0000323 a, B 20 0000325]!, BR [BR0000006987886] image!, LE [LE00008119] image!, NY [00148722, fragment of K] image!, P [P00631669]!, US [00066269] image!.
Alsophila platyphylla C.Presl (Presl 1851: 29).
– Type: FRENCH GUIANA • “ In Gujana gallica,” vicinity of Saül, ca 10 km NW from Eaux Claires; ca 03°37′ N, 53°12′ W; 400 m a.s.l.; G.S. Perrottet s.n.; lectotype: PR!, designated by Lehnert 2016; isolectotype: NY [0014874, fragment of PR] image!.
Alsophila gleasonii Maxon (Maxon 1925: 55).
– Type: GUYANA [BRITISH GUIANA] • Near Rockstone, in dense up-land forest; ca 05°58′26″ N, 58°31′09″ W; ca 100–120 m a.s.l.; 15 Jul.–1 Aug. 1921; H.A. Gleason 830; holotype: US [00066252] image!; isotypes?: NY [00148678] image!, US [00715386] image!.
Etymology
The specific epithet refers to the shape of the pinnules.
Selected material studied
COLOMBIA – Antioquia • Vereda Providencia, Anorí, 500 m arriba de la carretera por el camino de la retroescabadora desde la casa de Doña María; 7.3483333° N, 75.0208333° W; 300 m a.s.l.; 15 Jun. 2011; J. Colorado 732; HUA.
VENEZUELA – Amazonas, Dept. Río Negro • Cerro de la Neblina, Río Yatua, 6–8 km S of Camp 3; 1.03° N, 65.93° W; 1200–1600 m a.s.l.; 24 Dec. 1953; B. Maguire, J.J. Wurdack & G.S. Bunting 36870; US. – Bolivar, Mun. Bolivariano Angostura [= Raul Leoni] • 50 km al SW de Guaiquinima y 72 km al W de Karún; 5°18′ N; 63°59′ W; 230 m a.s.l.; A. Fernández & G. Aymard 4904; MO, UC. – Distrito Federal, Mun. Libertador • Cordillera de la Costa, al noreste de Guatire, excursion Fila Juan Torres-Fila Las Perdices por el Rio Guayabal hacia el pueblo Guayabal; 10.516667° N, 66.333333° W; 950–1000 m a.s.l.; 19 Feb. 1992; W. Meier 3415; UC.
GUYANA – Cuyuni-Mazaruni • Mt. Maringma, slope below sub-summit plateau; 5.20461° N, 60.5766° W; 1370 m a.s.l.; 22 Jun. 2004; H.D. Clarke, C. Perry, E. Tripp, S.R. Stern & D. Gittens 11931; US. – Potaro-Siparuni • Iwokrama Rainforest Reserve, Karupukari-Annai Road, summit of unnamed peak at end of 5 km transect; 4.471° N, 58.788° W; 700 m a.s.l.; 19 Mar. 1997; H.D. Clarke, S.A. Mori & S. Heald 4120; US. – Upper Takutu-Upper Essequibo • saddle between tops of Two-Head Mt, Kanuku Mts; 4.206° N, 59.117° W; 580 m a.s.l.; 2 Feb. 1994; M.J. Jansen-Jacobs, B.J.H. ter Welle, A. Chanderbali, U. Raghoenandan & V. James 3535; NY, US.
SURINAME – Marowijne • Marowijne [river], Nassau Mts, Plateau C; 4.83° N, 54.61° W; 500–550 m a.s.l.; 5 Feb. 2003; M.J. Jansen-Jacobs et al. 6556; U, UC, US. – Sipaliwini • Upper reaches of Grace Kreek, Tafelberg Mountain, headwaters of the Grace Kreek drainage; 3.893° N, 56.160° W; 700–790 m a.s.l.; 5 Jul. 1998; T. Hawkins 1892; L, MO, UC, US.
FRENCH GUIANA – Cayenne • D. Z. de Crique Jupiter, bassin du Sinnamary; 4.06° N, 53.16° W; 100 m a.s.l.; 25 Apr. 1991; J.J. de Granville 11511; CAY, L, NY, UC, US. – Saint-Laurent-du-Maroni • Mont Atachi Bacca, Region de lʼInini; 3.55° N, 53.91666° W; 500 m a.s.l.; 14 Jan. 1989; G. Cremers 10227; MO, NY.
BRAZIL – Amapá • Rivière Haut [= upper Río] Jari; 2.46° N, 54.76° W; 380 m a.s.l.; 19 Aug. 1993; J.J. de Granville, P. Acevedo-Rodríguez, A. Boyer & L.A. Hollenberg 12381; US. – Pará • Mun. Oriximiná Estação Ecológica Grão Pará, Córego próximo do acampamento; 1°16′47.4″ N, 58º41′28.5″ W; 475 m a.s.l.; 30 Aug. 2008; S. Maciel 983; MCT, STU. – Roraima • Lower slopes of Serra da Lua, by Igarape Camarao; 2°25–29′ N, 60°11–14′ W; 23 Jan. 1969; G.T. Prance, J.R. Steward, F. Ramos & L.G. Farias 9400; F, NY.
Description
Trunks 0.8–2.0(–8.0?) m tall, straight to decumbent, 4.0–5.0 cm diam., with persistent old petiole bases, sparsely aculeate; apices hidden between petioles; adventitious buds absent. Leaves to 165 cm long, held with petioles erect to ascending, blades ± planar, weakly arching. Petioles 27–44(–53) cm long, sparsely to strongly aculeate, prickles 2–3 mm long, dark yellowish brown to stramineous (Andes), or dark reddish brown (Guayana shield); aerophores to 10 × 1 mm, inconspicuously brown in dried material, whitish in fresh material; without adventitious (aphlebioid) pinnae at the petiole bases; petiole scales 15.0– 20.0(–23.0) × 2.5–4.0(–5.0) mm, lanceolate, tapering to linear tips, straight to falcate, weakly twisted, concordantly bicolorous, shiny dark brown to castaneous, with narrow, often abraded whitish margins, scales persistent in distal petiole parts, often reaching lower rachis, here only smaller than lower ones, remaining concordantly bicolorous (never paler or almost completely white); petiole scurf a tomentum of small branched clavate hairs 0.2–0.4 mm long, tan with brown parts, dark brown in general aspect, soon caduceus, persistent between spines. Blades 80–90 × 70–80 cm, bipinnate-pinnatifid, elliptic to obovate, chartaceous; dark green adaxially, often blackish when dried, olive green abaxially; (8–)10–12(–24?) pinna pairs, alternate, basal ones ½–⅓ the length of longest pinnae, weakly to strongly reflexed; apices abruptly reduced to non-conform apical sections, sometimes very broad and nearly gradually reduced. Leaf axes (rachises, costae and costules) stramineous to yellowish brown on both sides, often with a reddish tinge, inermous; adaxially with antrorsely curved uniseriate hairs 0.5–1.0 mm long (sparse to absent on costules), abaxially glabrous except for scurf remnants, containing appressed branched brown hairs (like on petioles), dark brown bullate squamules, 0.5–1.0 × 0.5 mm with subulate, rarely flattened or elongate tips (sparse to absent on rachis); junctions rachises/costae abaxially weakly swollen, each with an inconspicuous planar pneumathode, dark brown, elliptic, to 2.0 × 1.0 mm, area around it often black in dried specimens. Largest pinnae 37–45 cm long, sessile or stalked to 1.5 cm (proximal basiscopic pinnule reduced or fallen off), pinnae patent to weakly ascending, distally narrowly to broadly green alate, the pinnatifid terminal segment shortly decurrent into the costae. Largest pinnules 5.0–8.0 × 1.3–1.5 cm, linear-oblong, incised to ½ or more of their width (usually 2 mm between sinuses and costules), sessile, bases truncate to weakly cuneate, tapering from beyond the middle to obtuse to acute (rarely short-attenuate) tips; costules basally with a black ring going all around their bases (abscission layer), basally without aerophore; largest segments 8.0–10.0 × 2.5–4.5 mm, oblong, patent to ascending, distally weakly falcate, with entire to weakly dentate margins, tips rounded to obtuse; basal segments alternate, the lowest ones not remote from each other, sinuses narrowly triangular, acute, to 1.0–2.0 mm wide, sometimes closed; veins prominent abaxially and adaxially, midveins adaxially ridged, veins ending in cartilaginous segment margins; midveins yellowish brown abaxially and adaxially, lateral veins yellowish to greenish brown or blackish; glabrous adaxially except for occasional single hairs on the midveins, abaxially glabrous or with squamules and trichomidia like on the costules, trichomidia sometimes also between the veins; sterile and fertile veins mostly simple, rarely forked. Sori 0.8–1.0 mm diam., appearing ± medial when intact, closer to the margins when reduced to receptacles, parallel to the margins/midveins, on the back of veins, indusia absent; receptacles globose to ellipsoid, 0.2–0.3 mm diam.; paraphyses few to numerous, hyaline, white to tan, shorter than sporangia (0.2–0.3 mm). Spores not examined.
Distribution and ecology
Colombia, Venezuela, Guyana, Suriname, French Guiana, and northern Brazil (Fig. 2B) at elevations of (100–)140–1400(–1600) m a.s.l., in lowland rain forests on terra firme and premontane forest with Caribbean influence.
Remarks
The maximum reported height for the plant is 8 m (Maguire et al. 29929), which is exceptionally high for the species and likely erroneous. The highest number of pinna pairs is twice the average for the species and might have been intended as “24 pinnae in pairs”. Cyathea oblonga was resurrected from the synonymy of a loosely conceived C. pungens by Cremers & Boudrie (2007) based on their field observations in French Guiana. Here, both species overlap in their distribution, and show consistent differences in the anatomy and distribution of the petiole scales (relatively narrow, shiny dark brown with white margins, all along the petioles without getting paler in C. oblonga vs petiole scales usually restricted to petiole bases or if reaching further up then becoming paler to almost white in C. pungens) and the laminar indument (bullate squamules and scurf remnants on costae and costules brown to dark brown, well represented vs scurf and bullate squamules pale brown to white, scant).
Cyathea oblonga from higher elevations at the tablemountain bases differs from those in the lowlands of eastern Guayanan in having the axes abaxially not atropurpureous but stramineous to orange brown, and being stouter plants with thicker axes and larger pinnules. Plants here reported from northern Venezuela and the Andes of Colombia look more like the stouter tablemountain variety, and although having the diagnostic characters of that species (± medial sori, narrow petiole scales extending to the rachis), they may turn out to be aberrations of other taxa (mostly C. klotzschiana, presumably) after more scrutinous investigation in the field.
Precociously fertile plants with less divided blades than regular fertile plants are the basis for the synonym Alsophila gleasonii. Here, also the petiole scales tend to be smaller, but full in proportion to the smaller size of the plants. These individuals look like non-sympatric dwarf species of Cyathea, such as C. pseudonanna Lellinger from Panama, which is best distinguished by the denser, stiffer hairs abaxially on the rachises and the bluish sheen of the adaxial laminar side in fresh material.
description: Published as part of Lehnert, Marcus, Tejedor, Adrian, Kessler, Michael, Rodríguez Duque, Wilson D. & Gallego, Luis Fernando Giraldo, 2025, A reassessment of the Neotropical Cyathea pungens complex (Cyatheaceae), pp. 1-57 in European Journal of Taxonomy 988 on pages 20-24, DOI: 10.5852/ejt.2025.988.2883, http://zenodo.org/record/15282277