Cyathea pilosissima (Baker) Domin (1929a: 262)

Lehnert, Marcus, 2016, A synopsis of the exindusiate species of Cyathea (Cyatheaceae-Polypodiopsida) with bipinnate-pinnatifid or more complex fronds, with a revision of the C. lasiosora complex, Phytotaxa 243 (1), pp. 1-53 : 24-26

24. Cyathea pilosissima (Baker) Domin (1929a: 262) . ( Fig. 2A , 5 ). Alsophila pilosissima Baker in Hooker & Baker (1874: 457). Trichipteris pilosissima (Baker) Barrington (1978: 76) . Type:— PERU. San Martin: “Mt. Campana, East Peru,” [ca. 06°08’S, 74°48’W,] August 1856, R. Spruce 4322 (lectotype K-000227599!, here designated, isolectotypes B-20-0000285! [fragment], BM-000586105!, BR-0000006978495!/-0000006978648!, K-000227598!/-000227600!, NY-00148743! [fragment of K], W!).

Trunks to 3(–7) m tall, 5–9 cm diameter, covered with old petiole bases, spiny; epidermis densely covered with brown, narrowly lanceolate scales similar to petiole scales; apices hidden between petiole bases; without adventitious buds. Fronds to 240(–450) cm long, arching. Petioles to 90 cm long, proximally muricate to aculeate with spines to 3 mm long, dark stramineous to auburn, weakly shiny, without dense scurf, only few appressed tortuous white hairs and some cretaceous to bicolorous brown-white ovate squamules to 2 mm long, but densely and persistently hairy with erect, white to reddish brown, multicellular hairs to 4 mm long; petioles basally with a discontinuous line of aerophores (9–11 × 1 mm), pale orange brown in dried material; petioles persistently scaly in lower third. Petiole scales narrowly lanceolate, (15.0–)20.0–35.0 × 2.0–3.0 mm, relatively thin textured, bases weakly cordate, basifix to pseudopeltately attached, straight to falcate, apices long attenuate, undulate but not twisted; proximal scales concordantly bicolorous, shiny dark castaneous with white margins, distally getting paler and more and more discordantly bicolorous, auburn to orange-brown with whitish margins; differentiated margins fragile, the cell rows strongly exerted, forming short teeth but often abraded. Laminae to 150 × 80–120 cm, broadly ovate, bipinnate-pinnatifid, firm chartaceous, matte, dark green adaxially, often grayish or plumbeous when dried, grayish green abaxially; apices gradually reduced. Rhachises sparsely muricate in proximal parts, otherwise inermous, brown to dark stramineous abaxially and adaxially; pubescent with whitish to reddish brown multicellular hairs to 3.0(–4.0) mm long, adaxially appressed to spreading, abaxially spreading, persistent, leaving the cortex rough if abraded; sometimes with some appressed, white, tortuous hairs. Largest pinnae 45–60 cm long, ca. 9–12 pairs per frond, short-stalked 1.0– 1.5 cm, weakly ascending, alternate, inarticulate, distally narrowly green-alate, distal segments not decurrently adnate before ending in a pinnatifid apical section; basal pinna pairs smaller than the medial pinnae, weakly reflexed. Costae 2.0–3.0 mm wide, dark ochre to brown or orange brown abaxially, darker adaxially, inermous, without scurf, with whitish to tan, multicellular hairs to 3.0 mm long, adaxially antrorsely curved to appressed, abaxially spreading; junctures of costae and rhachises abaxially weakly swollen, each with an inconspicuous, planar to weakly protruding, elliptic aerophore to 2 × 1 mm, and a black (at least when dried) spot below it. Largest pinnules (30–)60–75 × (7–) 10–14 mm, sessile to subsessile (stalked to 1 mm), inarticulate, 1.3–2.0(–2.2) cm between the stalks/costules, lanceolate to linear-oblong, truncate to cuneate basally, long-acute to attenuate apically with serrate to crenulate margins; costules dark stramineous to ochre on both sides, adaxially strongly prominent, ridged, abaxially weakly to strongly prominent, moderately to densely hairy with whitish to tan, multicellular hairs to 2.0 mm long, adaxially curved to appressed, abaxially spreading; abaxially with few whitish to tan, bullate squamules to 2.0 mm long, with flat apices, and bicolorous brown-white, ovate-lanceolate scales to 3 mm long; costules basally without pneumathodes. Segments to 8.0(–11.0) × 3.0–5.0 mm, sessile, adnate, ascending, distally straight, tips obtuse to rounded, proximal segments alternate to subopposite, usually a bit shorter than following segments, never remote; sinuses acute, to 1.0 mm wide; margins crenate to serrate; margins not differently incised in proximal segments of a pinnule; veins planar to weakly protruding adaxially and abaxially, dark stramineous to yellowish green, ending in the margins; veins hairier abaxially than adaxially, with many erect, white to yellowish white, rarely reddish brown, multicellular hairs to 2.0 mm long on a them, also along the margins, abaxially also between the veins; midveins with few, white to light brown, bullate squamules to 2.0 × 0.5 mm with short apices; sterile and fertile veins simple, rarely forked. Sori (0.8–)1.0 mm diameter, medial, parallel to the margins, on the back or at the fork of veins, mature dark orange-brown; indusia lacking; receptacles globose, 0.2–0.3 mm diameter, sometimes subtended by a whitish lanceolate scale, paraphyses proximally twisted, distally straight, not contorted, whitish to tan, much longer than the sporangia (0.7–1.0 mm long) and persisting in over-mature sori. Spores white to pale yellow, exospore smooth, finely porate, perispore lacking ( Gastony 1979).

Distribution and habitat: — Peru, in evergreen lowland and premontane forest of the eastern Andean slopes at 200–1500 m.

Additional specimens examined: — PERU: Amazonas: Condorcanqui, Dist. Imaza , native community Yamayakat , 05º03’24”S, 78º20’17”W, 350 m, March 2002, A. Bonino 384 &402 ( UC!, MO!) ; Bagua, behind Parcelación Monterrico, 81 Km NE of Chiriaco , 13 km SW of bridge over Río Nieva , 04º45’S, 77º58’W, 200–300 m, 6 June 1986, S. Knapp & P. Alcorn 7612 ( UC!, MO!). Loreto: Vicnity of Aguaytia , along Río Aguaytia , 3 October 1972, T. B. Croat 20952 ( UC!, MO!). Pasco: Oxapampa, Dist. Palcazú, Reserva Comunal Yanesha, Cominidad Nativa San Pedro de Pichanaz , Sector Azulis, 10º26’44”S, 75º06’21”W, 910 m, 12 September 2005, A. Monteagudo et al. 9624 ( MO!), 10º29’34”S, 75º06’30”W, 520–640 m, 21 September 2005, A. Monteagudo et al. 10045 ( MO!), Comunidad Nativa Lomalinda- Yanesha, sector Nueva Aldea, 10º23’43”S, 75º05’12”W, 620–680 m, 14 October 2005, A. Monteagudo et al. 10585 ( MO!) ; Oxapampa, along road Chatarra-Pto. Bermudéz, 10º30’S, 75º03’W, 700 m, 9 July 2003, H. van der Werff et al. 18194 ( MO!). San Martin: San Martin, Ahuashiyacu waterfall, Cerro Escalera, along the road to Yurimaguas, in the valley with the spray of the waterfall, 06°28’S, 76°18’W, 850 m, 4 August 2002, M. J. M. Christenhusz et al. 1976 ( GOET) ; Huallaga, Dist. Saposoa , NW of San Antonio, Fundo Puero Nuevo La Union, 06º38.13’S, 77º20.41’W, 1100–1200 m, 17 August 2000, Quipuscoa et al. 2183 ( F!, UC!) ; Rioja, along road Rioja-Yorongos-La Florida , 1000 m, 29 March 2001, H. van der Werff et al. 16463 ( UC!, MO!) ; along road Yorongos-Uquihua , 1 April 2001, H. van der Werff et al. 16575 ( UC!, MO!) ; San Roque , 1350–1500 m, 1 February 1930, R. S. Williams 7741 ( F!) .

Remarks: —The type material at K consists of three sheets with lower pinnae, medial pinnae and apex, respectively. All bear the same handwritten annotation “ Alsophila pilosissima Baker ” but none of them has been indicated as type. Cyathea pilosissima has been reported from most parts of northern South America and eastern Central America but many of the records are based on misidentified material. Collections that agree well with the type material and the original description come only from the eastern foothills of the central Andes and the Amotape-Huancabamba region ( Weigend 2002), also known as Huancabamba Depression or Western Andean Portal ( Antonelli et al. 2009). Most of the Ecuadorian material determined as C. pilosissima belongs to C. calamitatis whereas Colombian material belongs either to C. senilis or C. margarita sp. nov., which see for further discussion.

Cyathea pilosissima is characterized by having hairs to 3 mm long on axes and on petioles, thin-textured dark castaneous petiole scales with white fragile margins, predominantly simple sterile and fertile veins, and having straight to weakly twisted paraphyses that are longer than the sporangia. No other species of Cyathea has such a combination of characters. Among the species treated here in detail, only C. parianensis has a dense pubescence on the petioles instead of squamellar scurf like C. pilosissima . Further characters shared between the two species are the whitish to tan bullate squamules on the laminae, the usually unforked fertile veins and the long but not contorted paraphyses, which suggests that both species are closely related. Cyathea parianensis differs in having shorter hairs on average (to 1 mm on petioles vs. to 2 mm on petioles in C. pilosissima ) and having veins that end before the segment margins on both sides, adaxially in distinct hydathodes (vs. veins at least abaxially seemingly ending in a marginal commissure). Both species are geographically well separated (Peninsula de Paria in Venezuela vs. Andes of northern Peru and adjacent Ecuador).

Cyathea senilis can be mistaken for C. pilosissima if petiole material is lacking because both are similar in pubescence and pinnule shape. A closer look at the whitish to pale brown bullate squamules on the laminae shows that they are concolorous with subulate tips in C. pilosissima but bicolorous with flattened dark brown tips in C. senilis . The ranges of both species do not overlap ( Cyathea senilis is confined to the Cordillera de la Costa in Venezuela and northern part of Colombia, C. pilosissima occurs only on the eastern Andean escarpment of Ecuador and Peru).

Most records of Cyathea pilosissima from the western Andean escarpment can be attributed to wrongly determined C. mucilagina , which occurs from Costa Rica through Panama and Colombia south to central Bolivia. Cyathea mucilagina differs from C. pilosissima in having alate rhachises (vs. non-alate in C. pilosissima ), concolorous orange-brown petiole scales (vs. bicolorous castaneous brown with narrow white margins) and relatively short paraphyses (of the same length as the sporangia vs. longer than the sporangia).

Among the species treated here, Cyathea pauciflora from Colombia and Venezuela comes closest to C. pilosissima regarding the shape of the pinnules and the segments. Cyathea pauciflora —as well as C. calamitatis , C. lasiosora , C. lockwoodiana , C. schlimii , and C. wendlandii — differs in having dark squamellar petiole scurf and forked fertile veins (vs. petioles with hairs instead of scurf and predominantly simple fertile veins in C. pilosissima ). Cyathea calamitatis , C. lockwoodiana , and C. schlimii are further distinguished by their abundant, heavily contorted paraphyses (vs. comparatively few, straight to weakly bent paraphyses in C. pilosissima ).

Figures

FIGURE 2. Cyathea spp. in the field: A1–D1. Trunk apex; A2–D2. Lamina apex; showing different expressions of abruptly reduced apices; A3–D3. Details of rhachichses, B–D at junctures with costae, showing presence and extend of pubescence and alae (D3). A. Cyathea pilosissima (Dept. San Martin, Peru). B. Cyathea calamitatis, sp. nov. (Prov. Morona-Santiago, Ecuador). C. Cyathea lasiosora (Dept. San Martin, Peru). D. Cyathea tortuosa (Prov. Zamora-Chinchipe, Ecuador).

FIGURE 5. Cyathea pilosissima. A. Lower petiole, showing pubescence and scales. B. Junction of rhachis and costa.C. Pinnule, adaxially. D. Fertile segments, abaxially and adaxially. (All from Monteagudo et al. 10585, MO)