Elaphoglossum sect. Polytrichia

Kessler, Michael, Moran, Robbin C., Mickel, John T., Matos, Fernando B. & Smith, Alan R., 2018, Prodromus of a fern flora for Bolivia. XXXV. Dryopteridaceae, Phytotaxa 353 (1), pp. 448-450 : 448-450

Key to the Bolivian species of Elaphoglossum sect. Polytrichia

1 Sterile blade bases long-decurrent; petioles nearly absent to 1/10 the sterile leaf length ................................................................ 2

– Sterile blade bases of various shapes, but never long-decurrent; petioles 1/4–4/5 the sterile leaf length ........................................ 3

2 Stem scales strongly flexuous throughout their length, concolorous; sterile blades 5–10 cm broad, apices acuminate to cuspidate ................................................................................................................................................................................... E. amazonicum

– Stem scales slightly sinuous for most of their length, distinctly darker towards their tips (bicolorous); sterile blades 2.5–6 cm broad, apices often long-caudate .................................................................................................................................. E. raywaense

3 Petioles 1/2–4/5 the sterile leaf length; leaves usually 4–15 cm long ........................................................................... E. hybridum

– Petioles 1/4–1/2 the sterile leaf length; leaves usually 15–45 cm long ............................................................................................ 4

4 Petiolar scales with obtuse apices and inrolled only proximally; scales of the blade margins rounded to cordate, flat ..................... ...................................................................................................................................................................................... E. decoratum

– Petiolar scales with acute to more usually attenuate apices, nearly flat to inrolled proximally or throughout; scales of the blade margins lanceolate to subulate, usually inrolled along their length (but nearly flat in the species of couplet 6) ............................. 5

5 Scales of the costae and margins <1 mm long, lanceolate, flat to slightly inrolled at the bases ...................................................... 6

– Scales of the costae and margins 1–5 mm long, hairlike, strongly inrolled at the bases and usually throughout ........................... 7

6 Blade bases attenuate to narrowly cuneate; scales of the costae and margins often darkened toward the tips; petioles 1–1.5 mm wide ................................................................................................................................................................................... E. kessleri

– Blade bases rounded to truncate; scales of the costae and margins concolorous; petioles 1.5–2 mm wide ........ E. semisubulatum