Hypolepis nigrescens Hook., Sp. Fil.

Schwartsburd, Pedro B., Navarrete, Hugo, Smith, Alan R. & Kessler, Michael, 2017, Prodromus of a fern flora for Bolivia. XXVI. Dennstaedtiaceae, Phytotaxa 332 (3), pp. 251-268 : 257

Hypolepis nigrescens Hook., Sp. Fil. 2(6): 66, 1852 [t. 90C, Figs. 1–3 in 1851], nom. cons.

Range:— Greater Antilles; mountains from southern Mexico to Colombia, southward to Bolivia (CO, LP), eastward to the intersection of Venezuela, Guyana, and northern Brazil.

Ecology:— Fairly common; terrestrial, erect to scrambling, especially in disturbed forests; 1300–2500 m, 900– 2800 m elsewhere.

Notes:— Herbarium specimens typically dry almost blackish. The laminar architecture resembles that of Paesia glandulosa . Hypolepis nigrescens is characterized by large blades (to 10 m long) with intermittent growth, petioles and rachises armed with curved, blackish spines, and costae adaxially with wings subtending the costules.

A specimen from LP (Nor Yungas, 5 km de Chuspipata, M. Kessler 11977 et al., UC) may be a hybrid between Hypolepis nigrescens and an unarmed species, but the collection is sterile and lacks a petiole.

Schwartsburd and Prado (2009) proposed the rejection of the name Hypolepis nigrescens (Schrad.) Nees , favoring H. nigrescens Hook. , which was later sanctioned ( Brummitt 2011).

Figures

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.

FIGURE 2. A–D. Hypolepis rigescens var. buchtienii (Buchtien 7014): A. Habit, B. Detail of petiole and rachis, abaxially, C. Pinnule, abaxially, D. Detail of veins, sori and pseuso-indusium, abaxially; E–H. Hypolepis minima (Jimenez 972): E. Habit, F. Detail of petiole, abaxially, G. Medial pinna, abaxially, H. Detail of veins, sori and pseuso-indusium, abaxially.

FIGURE 3. A–C. Pteridium esculentum subsp. gryphus (Gleason 423): A. Pinnule. B. Detail of ultimate segment, abaxially, showing sericeous veins. C. Cross section of ultimate segment, abaxial side up, showing the two types of hairs (gnarled hairs pointed by arrow).