Dryopteris Adans., Fam. Pl.

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

Dryopteris Adans., Fam. Pl. 2: 20. 1763.

Dryopteris has compact, erect rhizomes; persistent, conspicuous stipe base scales; multiple round meristeles arranged in a ring in stipe bases, with the two adaxial bundles enlarged (as in all Dryopteridaceae ); 2-pinnate or more complexly divided blades ( D. wallichiana , with pinnate-pinnatifid blades, is exceptional); often more developed pinnules basiscopically, at least proximally, on the blades; adaxially grooved rachises and costae; blades lacking acicular hairs, but often with small, short-stipitate glands; round, indusiate sori; and bilateral, often rugose or variously winged spores. Similar genera in Bolivia are Polystichum , which has slightly enlarged basal acroscopic pinnules and spinulose segment margins, Arachniodes , which has creeping rhizomes and anadromous blades, and Lastreopsis , which has flat (not grooved) rachises and costae. Dryopteris is taxonomically difficult, with polyploid complexes, apomixis, and frequent hybridization, at least in temperate regions ( Sessa et al. 2012 a, 2015). The tropical American species are in need of monographic study. Their relationship with other New World Dryopteris was studied by Sessa et al. (2012b).

Dryopteris appears to be most closely related to Arachniodes (also species-rich in eastern Asia), and, beyond that, to Polystichum and Cyrtomium ( Liu et al. 2007, Schuettpelz & Pryer 2007). Geiger & Ranker (2005) studied the infrageneric relationships within Dryopteris , especially with reference to the origin of the Hawaiian species, and included two Bolivian species (not closely related) in their sample.

Dryopteris comprises 300– 400 sp. ( Fraser-Jenkins 1986, Zhang et al. 2012, 2013), more if the limits are expanded, as done by some authors (e.g., Tryon & Tryon 1982), to include Arachniodes . Genera often segregated from Dryopteris , but now included within it by many, include Acrophorus , Diacalpe , Nothoperanema, and Peranema , all paleotropical (Zhang & Zhang 2012, PPG I 2016). The greatest number of species in Dryopteris occurs in north-temperate regions, particularly in eastern Asia ( China, Japan, and Himalayan regions); relatively few species occur in tropical mountains; there are about 20 species in the Neotropics.