Cyathea pastazensis (Hieron.) Domin, 1929

Lehnert, Marcus, Tejedor, Adrian, Kessler, Michael, Rodríguez Duque, Wilson D. & Gallego, Luis Fernando Giraldo, 2025, A reassessment of the Neotropical Cyathea pungens complex (Cyatheaceae), European Journal of Taxonomy 988, pp. 1-57 : 24-27

Cyathea pastazensis (Hieron.) Domin

Fig. 9

Cyathea pastazensis (Hieron.) Domin (Domin 1929: 263) . – Alsophila pastazensis Hieron. ( Hieronymus 1906: 232) . – Trichipteris pastazensis (Hieron.) R.M.Tryon ( Tryon 1970: 46) .

– Type: ECUADOR • Prov. Tungurahua, between Baños and Jivaría de Pintuc , Río Pastaza Valley ; 1870–1874; A. Stübel 995a; lectotype: B [ B 20 0000321 ]!, designated by Lehnert 2016; isolectotype: NY [ 00148730 , fragment of B]!. One excluded element (Stübel 988, B [ B 20 0000320 ]!) represents Cyathea tortuosa R.C.Moran ; other syntypes (Stübel 975, B [ B 20 0000319 a ]!; Stübel 876a, B [ B 20 0000319 b ]!) are not assignable to species.

Etymology

The specific epithet refers to the type locality, the Río Pastaza in Ecuador; today also a province of that country.

Selected material studied

COLOMBIA – Antioquia • Mun. San Carlos, between San Rafael and San Carlos ; 5.1544444° N, 75.0413889° W; 1600 m a.s.l.; 21 Feb. 2015; M. Lehnert 3162; BONN, HUA, Z • Mun. Anori, entre Barbosa y Medellín ; 7.252° N; 75.052° W; Bro. Henri-Stanislas 1708; MO, US. – Caquetá • Municipio de Belén de los Andaquíes, camino Anfaquí , reserva Andaquí , La Profunda ; 1°39′39.5″ N, 75°54′21.9″ W; 800–1000 m a.s.l.; 13 Mar. 2016; N. Castaño, D. Daly, E. Paki, J.A. Bustos, M. Lasso & A. Valencia 7714; COAH. – Cundinamarca • Yacopí; 5.4588111° N, 74.3080083° W; 1450 m a.s.l.; M. Morales 474; COL, FMB. – Meta • Municipio de Lejanias, vereda El Triunfo , ubicado a 3 km de las escuela; 3°35′38.4″ N, 74°05′52.3″ W; 1295 m a.s.l.; 21 Jul. 1998; R. López, J. Martínez, N. Cruz, M.A. Pinzón & R. Pinzón 4058; COAH. – Putumayo • Trocha de el Pepino al Rio Guineo , 1.084709° N, 76.707126° W; 1000 m a.s.l.; W. Hagemann & N. Leist 2051; COL. – Risaralda • Mun. Pereira, Hacienda Alejandría , Km 8 carretera Cerritos – La Virginia , extremos norte de parte ancha del valle del Rio Cauca , en bosque de galería a lo largo de la quebrada; 4.850° N, 75.867° W; 960 m a.s.l.; 8 Jul. 1995; P. Silverstone-Sopkin 7744; CUCV. – Tolima • Fresno; 1.426° N, 78.384° W; 1480 m a.s.l.; J. Cuatrecasas 9379; COL, F, US. ECUADOR – Prov. Morona-Santiago • Macas, roadside vegetation near town of Macas; 2°19′ S, 78°08′ W; 1100 m a.s.l.; 3 Jul. 1993; A. Fay & L. Fay 3957; MO, NY, QCNE • same collection data as for preceding; A. Fay & L. Fay 4066; MO, UC. – Prov. Napo • Cantón Archidona, road Hollín-Loreto , Km 17, near Río Hollín ; 0°41′ S, 77°41′ W; 1100 m a.s.l.; 14–22 Feb. 1989; F. Hurtado & J. Shiguango 1624; MO, UC. – Prov. Pastaza • About 0.5 km E of El Puyo ; [ca 01°29′59″ S, 77°58′43″ W]; [ca 1000 m a.s.l.]; 5 Oct. 1974; J. Hudson 845; MO, UC • on E side of El Puyo; 7 Oct. 1974; J. Hudson 896; MO, UC. – Prov. Sucumbios • Shishicho ridge, Alto Aguarico drainage, above (S of) Río Cofanes , W of Puerto Libre , NW of Lumbaqui , access from Río Sieguyo , below Shishicho Camp ; 0°12′01.3″ N, 77°31′54.3″ W; 1500–1570 m a.s.l.; 13 Aug. 2001; R. Aguinda, N. Pitman & R.B. Foster 1302; F, UC. – Prov. Zamora-Chinchipe • Nangaritza canton, Parroquia Guayzimi , Campamento Militar Miazi , al sur del río Nangaritza ; 4.27° S, 78.70° W; 1060– 1000 m a.s.l.; 21 Oct. 1991; C.E. Cerón, M. Chango, V. Tapur & G. Aymard 16836; MO .

PERU – Amazonas • Bagua, Soldado Oliva, carretera Bagua-Imaza ; [ca 5.304° S, 78.388° W]; 660 m a.s.l.; 6 Feb. 1999; C. Díaz et al. 10642; MO .

Description

Trunks to 3.5 m tall, straight, 5.0–8.0 cm diam. (records of 30 cm diam. likely include layer of adventitious roots), covered with old petiole bases, due to these sparsely to strongly aculeate, in lower parts petioles rotting; apices hidden between petioles; adventitious buds absent. Leaves to 275 cm long, held with petioles erect to ascending, lamina ± planar, weakly arching. Petioles 20–45(–59) cm long, sparsely aculeate, prickles to 3 mm long, dark yellowish brown to stramineous, sometimes basally darker brown; aerophores to 20 × 1 mm, in a ± continuous line on each side, inconspicuous in dried material, whitish in fresh material; without remote (aphlebioid) pinnae at the petiole bases; petiole scales 20.0–32.0 × 2.5–5.0 mm, lanceolate to ovate-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, appearing as small dark dots or irregular stars on the yellowish brown epidermis, persistent but easily abraded.Blades (110–)180–255 × 90–105 cm, bipinnate-pinnatifid, ovate-elliptic to obovate, chartaceous; dark olive-green adaxially, often blackish when dried, olive green abaxially; smaller plants with long petioles and ovate-elliptic blades with 8–10 pinna pairs, basal ones ca ½ the length of longest pinnae, larger plants with short petioles and basally tapering blades with 16–18 pinna pairs, basal ones ca ⅓ the length of longest pinnae, patent to weakly reflexed; pinnae alternate; apices gradually reduced. Leaf axes (rachises, costae and costules) stramineous to yellowish brown on both sides, sparsely aculate in lower half, otherwise inermous; adaxially with antrorsely curved uniseriate, reddish brown hairs 0.5–1.0 mm long, abaxially with scurf remnants, costae and costules also with dark brown, erect shell-like to bullate squamules, 0.5–1.0 × 0.5 mm with subulate, rarely flattened or elongate tips, larger flat squamules to 2 × 1 mm rare or absent; junctions rachises/costae abaxially weakly swollen, each with an inconspicuous planar pneumathode, dark brown, elliptic, to 4.0 × 2.5 mm, area around it often black in dried specimens (foliar nectary). Largest pinnae 37–45 cm long, sessile (appearing stalked if proximal basiscopic pinnule fallen off), pinnae patent to weakly ascending, distally narrowly to broadly green alate, the pinnatifid terminal segment shortly decurrent into the costae. Largest pinnules 8.0–11.5 × 2.0– 2.5 cm, linear-oblong to linear-lanceolate, incised to ½ or more of their width (usually 2–3 mm between sinuses and costules), sessile, bases on smaller ones truncate to weakly cuneate, in larger ones truncate to weakly cordate, smaller pinnules (especially in lower pinna) with obtuse to rounded tip, larger pinnules tapering from beyond the middle to short-attenuate tips; costules basally with a black ring going all around their bases (abscission layer); largest segments 12.0–15.0 × 2.5–4.0 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 to elliptic, acute, to 1.0 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 except for some dark brown bullate squamules and trichomidia on midveins, absent between the veins; sterile and fertile veins mostly simple, regularly forked in the tips of lager segments. Sori 0.8–1.0 mm diam., medial to supramedial (sometimes appearing submarginal when sori still complete), parallel to the midvein or in triangular lines, on the back of veins or in fork of veins, indusia absent; receptacles globose to ellipsoid, 0.2–0.3 mm diam.; paraphyses few to numerous, hyaline, brown to tan, shorter than sporangia (0.2–0.3 mm). Spores not examined.

Distribution and ecology

Colombia (Cordilleras Occidental and Central), Ecuador and northern Peru (eastern Andean slopes) ( Fig. 2B ) at elevations of (310–) 850–1600 m a.s.l., dubious records also from the western escarpment ( Ecuador: El Oro; Colombia: Chocó); in the understory of lower montane forest, preferably in small valleys (quebradas) and near water courses.

Remarks

The syntypes of Alsophila pastazensis have been regarded to represent one species, but we consider them to belong to at least two species, one of them Cyathea tortuosa R.C.Moran. This is supported by recent observations by the first author at the Jardin Botanico las Orquideas, a private reserve near Puyo, Ecuador. Both species grew only a few meters apart in the dense forest understory, but each with a specific habit, with C. pastazensis having a trunk covered in old petiole bases and funnel shaped crown, and C. tortuosa with a clean-shed trunk and patent leaves.

Cyathea pastazensis is best described as a Cyathea floribunda with darker, concolorous squamules on the blades because both have sessile pinnae and round-tipped segments. However, C. pastazensis shows the typical leaf architecture of C. pungens with the pinnules of the lower pinnae being blunt-tipped whereas the pinnules of the distal pinnae are decidedly more acute (vs all equally blunt-tipped in C. floribunda , as observed so far). In the contact zone of the ranges of both species in southern Ecuador and northern Peru, it almost looks like a fluid transition between the two morphologies in a large shared range ( Fig. 2B ); but as we interpret it, C. pastazensis extends south along the lowland forests of the Amazon basin whereas C. floribunda reaches north along the Andean foothills.

Both Cyathea pastazensis and C. floribunda differ from C. pungens in soral lines that follow the midveins, thus forming parallel lines across the whole pinnule; in C. pungens , the soral lines are parallel to the segment margins, thus shaped in a zig-zag pattern across the whole pinnule. In C. pastazensis and C. floribunda , pinnae and pinnules are sessile whereas in C. pungens , at least the largest pinnae are clearly stalked, creating a visible gap between rachis and blade; pinnules tend to be remote from the costae, too, but this character is more clearly developed in eastern Amazonian population of C. pungens .

Cyathea werffii grows in the same region (e.g., Baker 5699, MO, NY), but has smaller leaves with stalked lower pinnae (vs all sessile in C. pastazensis ), smaller pinnules with blunt, often widened tips, appearing almost rectangular; it also has scarcer scaly indument on the axes than C. pastazensis .

Figures

Fig. 9. Cyathea pastazensis (Hieron.) Domin. A. Petiole with scurf and scales, small individual (Lehnert 3162, BONN). B. Pinna, silhouette. C. Pinnule, adaxially (M. Lehnert 3162, BONN). D. fertile segment, abaxially (Lehnert 3162, BONN).

Fig. 2. Distribution of taxa of the Cyathea pungens complex except C. pungens (Wild.) Domin s. str. A. Cyathea dombeyi (Desv.) Lellinger (blue triangles), C. pycnocarpa (Kunze) Domin (green dots), C. squamata (Klotzsch) Domin (black squares), C. werffii R.C.Moran (magenta dots). B. Cyathea floribunda (Hook. & Baker) Domin (black squares), C. klotzschiana Domin (black dots), C. oblonga Domin (orange diamonds), C. pastazensis (Hieron.) Domin (blue triangles), C. praecincta (Klotzsch) Domin (green dots); note that the ranges of C. klotzschiana in the north and C. floribunda in the south do not overlap but are separated by C. pastazensis.