Enterosora Baker, Timehri

Smith, Alan R., Kessler, Michael, León, Blanca, Almeida, Thaís Elias, Jiménez-Pérez, Iván & Lehnert, Marcus, 2018, Prodromus of a fern flora for Bolivia. XL. Polypodiaceae, Phytotaxa 354 (1), pp. 448-450 : 448-450

Enterosora Baker, Timehri 5: 218. 1886.

Enterosora was revised by Bishop & Smith (1992) and is similar to Ceradenia ; both genera generally lack hydathodes on the blades adaxially, but the former lacks soral paraphyses. Enterosora may also be confused with Zygophlebia , but that has brown soral paraphyses and deeply pinnatifid to pinnatisect blades (lobed less than than 3/4 of the distance to the midribs in Enterosora ). Species of Enterosora have parenchyma with numerous, large intercellular air spaces in the mesophyll, and this feature results in a spongiose texture to the blades. Sori are elongate to round, and often somewhat sunken in the leaf tissue. Eight species occur in the Neotropics and two (one of which is the same as one of the neotropical ones) in Africa and Madagascar ( Bishop & Smith 1992); two widespread species are known in Bolivia, and both are rare.

Phylogenetic studies suggest that Enterosora is close, and perhaps sister, to Ceradenia , but sampling is so far inadequate ( Ranker et al. 2004, Sundue et al. 2010, Sundue et al. 2014); it is still unclear whether Zygophlebia can be adequately separated from Enterosora ( Bauret et al. 2017) . The close relationship of these three genera was suspected on the basis of morphology. Beyond these relationships, Enterosora and its two allies are most closely related to other New World grammitid genera—well removed from affinities to Old World grammitids.