Cyathea calamitatis Lehnert, 2016

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 : 11-14

19. Cyathea calamitatis Lehnert , sp. nov. ( Figs. 1 , 2B )

A new species of exindusiate Cyathea that has almost identical petiole scales and scurf as the widespread C. lasiosora but differs in having longer, contorted and persistent paraphyses and a denser, more persisting pubescence on the abaxial laminar surface on and between the veins. The pinnules do not change their shape in the same way with increasing size (remaining sessile and becoming oblanceolate in C. calamitatis vs. becoming short-stalked and more or less triangular in C. lasiosora ).

Type: — ECUADOR. Zamora-Chinchipe: Campamento Shaime (Shaimi) along Río Nangaritza, trail to the ridge N of the village, trail starting from behind the visitor cabañas, 04°19’S, 78°40’W, 930–1100 m, 8 November 2004, M. Lehnert 1531 (holotype QCA! [2 sheets], isotypes GOET!, UC!).

Trunks to 2.6 m tall, slender, to 4.5 cm diameter, old petiole bases not falling off cleanly but rotting soon; epidermis densely covered with dark brown, lanceolate scales similar to petiole scales; apices hidden between petiole bases; without adventitious buds. Fronds to 260 cm long, spirally arranged along trunk, not forming distinct fascicles at apices; arching to pendent. Petioles to 45 cm long, proximally muricate with spines to 1 mm long, dark brown to dark auburn, matte, with dense scurf consisting of appressed reddish brown trichomidia and branched hairs, uniseriate hairs absent; petioles basally on each side with a discontinous line of pale brown lenticels to 20 × 1.5 mm. Petiole scales lanceolate to ovate lanceolate, to 15.0 × 3.0 mm, thick-textured, bases weakly cordate, basifix to pseudopeltately attached, straight to falcate, apices long acute, flat; scales concordantly bicolorous, dark castaneous to almost black with brown margins; differentiated margins firm, the cell rows not strongly exerted. Laminae to 215 × 120 cm, bipinnate-pinnatifid, firm herbaceous to chartaceous, weakly shiny, dark-green adaxially, blackish when dried, dark olive green abaxially; apices gradually reduced or abruptly reduced to a rather broad, non-conform section. Rhachises inermous, brown to dark auburn abaxially and adaxially, pubescent with whitish to tan multicellular hairs 1.0– 1.5 mm long, appressed and persistent adaxially, spreading abaxially, leaving a scabrous epidermis if abraded. Pinnae to 60 cm long, stalked to 5.5 cm, 7–10 pairs per frond, patent, alternate or few opposite, inarticulate, distally narrowly green-alate, distal segments weakly decurrently adnate before ending in a pinnatifid apical section; basal pinna pairs not much smaller than the medial pinnae, weakly reflexed. Costae to 3 mm broad, inermous, dark ochre to castaneous abaxially, darker adaxially; with whitish to tan, uniseriate hairs 1–2 mm long, adaxially appressed, abaxially uniseriate hairs spreading, leaving a scabrous surface when abraded; junctures of costae and rhachises weakly swollen abaxially, each with an inconspicuous, planar elliptic aerophore to 4 × 2 mm. Largest pinnules to 125 × 19 mm, sessile to subsessile (stalked 1(-2) mm), inarticulate, to 2 cm between the stalks/costules, lanceolate to linear-oblong to oblanceolate, truncate to weakly cordate basally, attenuate apically with crenate to crenulate margins; costules blackish brown, rarely dark carnose to atropurpureous adaxially and abaxially; adaxially strongly prominent, ridged, and densely hairy with whitish to tan, multicellular hairs, smaller ones antrorsely curved to appressed, to 1.0 mm long, larger ones spreading, to 2.0 mm long, abaxially weakly to strongly prominent, densely and persistently hairy with many erect, whitish to reddish brown hairs to 1.5(–2.0) mm long, also with few reddish brown, flat to subbullate squamules to 2.0 mm long; costules basally without pneumathodes, blackened in dried specimens. Largest segments to 11 × 4 mm, sessile, adnate, proximal ones patent, distal ones ascending, distally weakly falcate, tips obtuse to rounded, proximal segments opposite or nearly so, nearly the same size of following segments, never remote; sinuses acute to obtuse, to 2 mm wide; margins crenulate to subentire; margins not differently incised in proximal segments of a pinnule; veins planar adaxially and abaxailly, blackish to dark carnose, ending in the margins; veins adaxially and abaxially with few to many erect, whitish to reddish brown, multicellular hairs to 2.0 mm long on them, also along the margins but not between the veins; midveins with few, reddish brown bullate squamules to 2.0 × 0.5 mm; sterile veins simple or forked, fertile veins forked. Sori 0.8–1.0 mm diameter, medial, at vein forks, mature dark orange-brown; indusia lacking; receptacles globose, relatively small, 0.2–0.3 mm diameter, paraphyses numerous, heavily contorted, whitish to tan, longer than the sporangia (0.5–0.6 mm long) and persisting in over-mature sori. Spores not investigated.

Distribution and habitat: —Southern Ecuador and northern Peru, in moist premontane forest at 600–1100 m.

Etymology: —Named for the troublesome intermediate morphology of the species (Latin calamitas = calamity, trouble)

Additional specimens examined (paratypes): — ECUADOR. Morona-Santiago: Shuar community Wisuí, trail to Cerro Wisuí, 02°05.449’S, 77°45.681’W, 820 m, 9 March 2013, M. Lehnert 2664 ( QCA!, STU!) ; Limon-Indanza, region of Cordillera del Cóndor, Centro Shuar Kunakus, Valle del Río Coangos, 03º03’14”S, 78°13’39”W, 630 m, 6 October 2005, A. Wisum et al. 233 ( MO!). Pastaza: Río Bobonaza , between oil exploration camp Chichirota and Destacamento Cabo Pozo, 02°25’S, 76º39’W, 300 m, 20 July 1980, Øllgaard et al. 34893 ( AAU!, QCA!, UC!) .— PERU. Amazonas: Prov. Bagua, Distr. Imaza, Comunidad de Yamayakat, 05°03’24”S, 78°20’17”W, 600 m, 29 May 1997, R. Vásquez et al. 23822 ( MO!). Huanuco: Prov. Pachitea, region of Pucallpa, western parts of the Sira mountains and adjacent lowlands, from ca. 20 km to 24 km SE of Puerto Inca, crest of the mountain range going west to east, […] “Campamento Sira”, 09°28’S, 74°47’W, 800 m, 19 March 1988, B. Wallnöfer 14-19388 ( W), 20 March 1988, B. Wallnöfer 14-20388 ( W). Ucayali [as Loreto]: Bosque Nacional Alexander von Humboldt (Pucallpa-Tingo Maria rd Km 86), [ca. 09°09’S, 75°45’W, 800–1000 m,] 7 September 1980, P. Maas et al. 4507 ( Z) .

Remarks: —The plants recognized here as Cyathea calamitatis have the abundant contorted long paraphyses and the long spreading hairs on the leaf axes of C. lockwoodiana but have the dark brown, thick textured petiole scales and the reddish brown laminar squamules of C. lasiosora . The largest pinnules of these intermediate plants can reach 10 cm in length, and then are sessile with the segments remaining round to obtuse and the pinnule outline linear-lanceolate to oblanceolate. They agree well in this respect with C. lockwoodiana . In contrast, pinnules of luxuriant plants of C. lasiosora rarely surpass 7.5 cm in length but tend to be short-stalked with the segments more oblong with acute, crenulate tips and to have a more pronounced lanceolate to weakly triangular outline.

Cyathea calamitatis may be the basis for Tryon`s assumption that C. lasiosora and C. pilosissima may not be wholly distinct ( Tryon 1986). The spreading red hairs and the density of the pubescence of C. calamitatis are reminiscent of C. pilosissima but both species are easily distinguished by the petioles (scurfy, lacking hairs, epidermis dark brown and with appressed, dark brown ovate-lanceolate scales in C. calamitatis vs. hairy, lacking scurf, epidermis stramineous to dull brown, and with ± spreading, brown to reddish brown lanceolate scales in C. pilosissima ). Laminar samples alone can also be distinguished by the paraphyses (heavily contorted and persistent in C. calamitatis vs. straight and often fragmenting in C. pilosissima ) and the laminar squamules (reddish brown vs. stramineous to pale brown).

Recent field observations from the northern occurrence in Ecuador, Prov. Morona Santiago, have revealed that Cyathea calamitatis grows in sizeable populations in a relatively narrow elevational range. The species marks the limit were the microclimate rather suddenly changes from the warm lowland regime to the cooler mountain climate with regular fogs, indicated also by a notable increase of the bryophyte abundance and epiphyte diversity. Cyathea calamitatis , however, soon disappears at higher elevations where the undergrowth becomes denser. This correlation can be corroborated for the southernmost registry in Peru (B. Wallnöfer, personal communication).

None of the above-mentioned similar species ( Cyathea lasiosora , C. lockwoodiana , C. pilosissima ) where found at these locations, arguing against a hybrid status of C. calamitatis . From personal observation in the Rio Mayo Valley (Prov. San Martin, Peru), which encompasses the type localities of C. lasiosora and C. pilosissima , I would characterize C. pilosissima as being adapted to warmer, drier climates than C. calamitatis because I found it most numerous on west-facing slopes and well-drained substrates on white sandstone. I observed it only once growing together with C. lasiosora at the first crest along the road from Tarapoto to Yurimaguas (Prov. San Martin, Peru). In the Andes, Cyathea lasiosora —like C. calamitatis –—is restricted to the east facing slopes of the piedmont region, where rainfalls are higher, but it is most frequent in the Amazon basin where C. calamitatis is absent.

Within a population, Cyathea calamitatis shows more variation in the size and shape of fertile pinnules than it is reflected by most collections. Most notably, the smallest and the largests pinnules are sessile, whereas intermediate ones (ca. 6–7 cm long) may have a clearly visible stalk. This weakens the distinction from C. lasiosora , in which a positive correlation between pinnule size and presence/length of stalk is observed. However, C. calamitatis is constant in the clearly visible, strigose pubescence of the rhachises, which contrast with its scurfy petioles (vs. rhachsises with sparse, inconspicuous flaccid hairs, thus at first sight not contrasting with the petiolar indument in C. lasiosora ).

Van der Werff et al. 19178 (GOET, MO) has large (90 × 16 mm) oblanceolate pinnules with almost entire segments. It resembles in this respect Cyathea calamitatis but hairs are absent from the veins except on margins and along midveins abaxially, and petiole material, which is needed for secure identification, was not available. Shape and color of the laminae match C. calamitatis but the hairs, though abundant and long for C. lasiosora , are too pauper for C. calamitatis .

Figures

FIGURE 1. Cyathea calamitatis, sp. nov. A. Petiole scale (petiole identical with C. lasiosora, Figure 3A). B. Detail of petiole scurf. C. Pinnule, adaxially. D. Fertile segment, abaxially. (All from the isotype Lehnert 1531, UC)

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).