Didymoglossum kapplerianum (J.W.Sturm) Ebihara & Dubuisson, Blumea

Kessler, Michael & Smith, Alan R., 2017, Prodromus of a fern flora for Bolivia. X. Hymenophyllaceae, Phytotaxa 328 (3), pp. 201-226 : 205

Didymoglossum kapplerianum (J.W.Sturm) Ebihara & Dubuisson, Blumea 51: 236. 2006.

= Didymoglossum ekmanii (Wess.Boer) Ebihara & Dubuisson, Blumea 51(2): 236. 2006.

= Microgonium kapplerianum (J.W.Sturm) Pic.Serm., Webbia 31(1): 250. 1977.

= Trichomanes kapplerianum J.W.Sturm, Fl. Bras. 1(2): 276. 1859.

= Trichomanes ekmanii Wess.Boer, Acta Bot. Neerl. 11: 319, f. 33. 1962.

Range: —Antilles; Central America to Bolivia (BE, CO, LP, PA) and Brazil.

Ecology: —Uncommon; epiphytic and on wet rocks, in humid forests; to 500 m.

Notes: —Specimens with continuous (vs. interrupted) submarginal veins bordered on the outside by a row of cubical (vs. lengthened) cells have been separated as Didymoglossum ekmanii , but these differences do not seem to be a reliable distinction. In contrast with other Bolivian species, D. kapplerianum , in subg. Microgonium , has blades lacking marginal hairs but with distinct submarginal veins; the sori are wholly immersed, without lips and not dark-edged.

Lellinger (1991) attempted to distinguish D. kapplerianum (South America) from D. ekmanii (Antilles, Mesoamerica) , but we think them synonymous, as have some other investigators (e.g., Tryon & Stolze 1989). However, according to Ebihara et al. (2007) and Senterre et al. (2017), Colombian D. ekmanii and D. kapplerianum from Guadeloupe do not form a monophyletic cluster, hence contradicting the synonymization of the two species. Expanded molecular and morphological analyses of these and related taxa are needed, and in the interim we use the oldest available name for Bolivian populations.

Didymoglossum krausii (Hook. & Grev.) C.Presl , Hymenophyllaceae (Presl) 23. 1843 [ Abh. Königl. Böhm. Ges. Wiss., ser. 5, 3: 115. 1843].

= Trichomanes krausii Hook. & Grev., Icon. Filic. 2: pl. 149. 1830.

Range: —Florida; Antilles; southern Mexico to Bolivia (BE, CO, LP, SC), Paraguay, and northern Argentina.

Ecology: —Common; epiphytic and on wet, mossy rocks, in humid forests; to 800(–1100) m.

Notes: —Variable in the degree of laminar dissection, the width of the segments, and the degree to which the sori are immersed. Most similar to D. reptans , from which it differs in having false veinlets mostly not connected, parallel and very close to the blade margins and sori immersed in the blade tissue. It also generally occurs at lower elevations, and the fronds are generally smaller.