Cyathea ruttenbergiae A.Tejedor & F.Areces

Cyathea ruttenbergiae A.Tejedor & F.Areces View in CoL

Cyathea ruttenbergiae A.Tejedor & F.Areces [as C. ruttenbergii ] ( Tejedor & Areces-Berazain 2018: 280).

– Type: PUERTO RICO • Río Grande, El Yunque National Forest , route 191, km 4.8; 18.338° N, 65.764° W; 210 m a.s.l.; 30 Jul. 2017; F. Areces 1160; holotype: UPRRP!, GoogleMaps isotype: NY GoogleMaps !.

Etymology

The epithet honors Kathy Ruttenberg, US American artist and sculptor.

Selected material studied

PUERTO RICO [USA] • Luquillo Mts., Rt 988 ( Sabana Rd. ); D.S. Conant 4171 with J. DeCamp; VT.

Description (diagnostic characters)

Trunk to 2 m tall, 5–7 cm diam.; leaves to 190 cm long, ascending-arching, petioles to 60 cm long, petiole scales ovate-lanceolate, 10.0–15.0 × 4.0–5.0 mm, shiny, concordantly bicolorous brown with lighter translucent yellowish to cream margins, fragile, often abraded; blades to 90 × 70 cm; 6–7(–8) pinna pairs, basal ones strongly reflexed ca ½ the length of the longest pinnae; apices abruptly reduced. Pinnae to 45 cm long, ascending, stalked to 2.5 cm, alternate; pinnules to 12 × 2.5 cm, stalked to 4 mm, inarticulate, 2–3 cm between the stalks, elliptic-lanceolate, bases asymmetric, with a gap or missing segment on one side, tips attenuate with crenulate margins; costules green on both sides, abaxially strongly prominent, ridged, with sparse tortuous white hairs to 1 mm and flat, lanceolate whitish to beige squamules to 1.5 mm. Segments to 15 × 6 mm, basal segments strongly asymmetric, if slightly remote then connected by wide green wing; sinuses oblong to acute to 3.0 mm wide, never occluded; margins crenulate; midveins with few, tortuous, white hairs to 1 mm; veins simple or forked; sori submarginal. (Full description in Tejedor & Areces-Berazain 2018.)

Distribution and ecology

Endemic to Puerto Rico, in the understory of perhumid rainforests.

Remarks

Almost identical to the regular form of Cyathea pungens proper, but seems to have fewer pinna pairs per leaf, with basal pinnae not as much reduced as in C. pungens and larger pinnules (to 12 × 2.5 cm in C. ruttenbergiae vs mostly 5–8 × 1.5–1.8 cm in C. pungens ); due to the larger pinnules, also fertile veins are often forked (vs generally simple in C. pungens ). Most notable are the blunt sinuses between the lowest segments of the largest pinnules; the very few samples of C. pungens that have pinnules wider than 2 cm still have acute sinuses between the lowest segments and not the blunt ones of C. ruttenbergiae .