Prodromus of a fern flora for Bolivia. XXVI. Dennstaedtiaceae Author Schwartsburd, Pedro B. Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Av. P. H. Rolfs s. n., Viçosa, MG, Brazil, CEP 36570 - 900 Author Navarrete, Hugo Herbario QCA, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076 y Roca, Quito, Ecuador. Author Smith, Alan R. University Herbarium, 1001 Valley Life Sciences Bldg. # 2465, University of California, Berkeley, CA 94720 - 2465 Author Kessler, Michael Department of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, CH- 8008 Zurich, Switzerland text Phytotaxa 2017 2017-12-22 332 3 251 268 http://dx.doi.org/10.11646/phytotaxa.332.3.2 journal article 10.11646/phytotaxa.332.3.2 1179-3163 13723580 Hypolepis periculosa Schwartsb. , sp. nov. ( Fig. 1E–G ) Spiny, reddish brown petioles and rachises, costae with long catenate-acicular and catenate-glandular hairs, laminar tissue between the veins abaxially with catenate-glandular hairs, and ciliate pseudo-indusia. Type:— BOLIVIA . La Paz : Prov. Nor Yungas, a 5 km de Chuspipata hacia Coroico, 16°23’S , 67°48’W , 2700 m , 19 September 1997 , M . Kessler 12087 with J . Gonzales, K . Bach & A . Portugal ( holotype UC !; isotypes GOET !, LPB !) . Plants terrestrial. Rhizomes 3–6 mm diam.; hairs catenate-acicular, reddish brown, 1–3 mm long, 10–30-celled. Leaves complete not seen, determinate, scandent, probably 2 m long or more; petioles complete not seen, ca. 5–7 mm diam., entirely reddish brown, glabrescent, rugose, the spines conspicuous, straight, 0.3–1.2 mm long; blades (complete not seen) tripinnate-pinnatifid to quadripinnate-pinnatifid proximally, at least 1.4 × 1.2 m ; rachises straight, proximally reddish brown, stramineous above, spiny, rugose, glabrescent, with catenate-acicular and catenate-glandular hairs; basal pinnae ca. 60 × 22 cm , subequilateral; costae abaxially and adaxially pilose with two kinds of hairs, the first kind of hair catenate-acicular, hyaline with reddish cross-walls, 0.8–1.8 mm long, 8–18-celled, the second kind of hair catenate-glandular, hyaline with reddish cross-walls, 0.3–0.5 mm long, 4–6-celled; costules abaxially with catenate-glandular hairs, adaxially glabrescent; veins abaxially with catenate-glandular hairs, adaxially glabrescent; laminar tissue between the veins abaxially with catenate-glandular hairs, adaxially glabrous; laminar margins glabrous; sori marginal; pseudo-indusia proximally greenish, distally hyaline, the margins copiously ciliate. Range:— Endemic to Bolivia ( LP ) ; known only from the type collection. Ecology:— Rare; scandent terrestrial, in evergreen forests; 2700 m . Etymology:— The epithet periculosa ( Latin ) means “dangerous”, an allusion to its densely spinulose petioles and rachises. In addition, it was collected along the infamous “death road” to Coroico, well known for its precipitous drops. Notes:— Hypolepis periculosa is characterized by spiny, reddish brown petioles and rachises, costae with long catenate-acicular hairs ( 0.8–1.8 mm long, 8–18-celled) and catenate-glandular hairs, costules, veins, and laminar tissue between the veins (abaxially) with catenate-glandular hairs, and ciliate pseudo-indusia ( Figs. 1E–G ). It differs from H. rigescens by the reddish brown, stouter ( 5–7 mm diam.) petioles ( vs. petioles proximally purplish or blackish, golden brown distally, 2.5–6 mm diam.), the copiously ciliate pseudo-indusia ( vs. margins crenate to dentate, rarely with one or two cilia), and by occurring at much higher elevation. In addition, these two species differ slightly in their indument: the catenate-acicular and the catenate-glandular hairs of H. periculosa are longer. FIGURE 1. A–D. Hypolepis woodii ( Solomon 16418 ): A. Proximal pinna, B. Detail of petiole and rachis, abaxially, C. Ultimate pinnule, abaxially, D. Detail of veins, sori and pseuso-indusium, abaxially. E–G. Hypolepis periculosa ( Kessler 12087 ): E. Detail of petiole and rachis, abaxially, F. Pinnule, abaxially, G. Detail of veins, sori and pseuso-indusium, abaxially. The type of Hypolepis periculosa was previously identified as Hypolepis viscosa H.Karst. ( Smith et al. 1999 ) , but that species has inermous petioles and rachises, and pilose laminar margins, thus differing from H. periculosa . Hypolepis viscosa occurs in Colombia , Venezuela , and Hispaniola.