Marattiaceae Kaulf.

Terrestrial (NZ) or occasionally epiphytic (not NZ) ferns. Rhizomes usually erect, obscured by pairs of large stipules protecting the young croziers. Fronds monomorphic (NZ) or dimorphic (not NZ). Stipes and stipules often bearing conspicuous lenticels. Laminae undivided, palmately divided, or 1 to many times pinnately divided (2-pinnate in NZ), bearing hairs and scales. Pulvini present at base of lamina, bases of pinnae, and sometimes on the stipe. Veins free and generally undivided or once-forked (NZ), or reticulate (not NZ); false veins sometimes present between true veins (not NZ). Sori elongate along veins, close to lamina margin, superficial (NZ) or sunken into the lamina or stalked (not NZ), composed of two rows of sporangia either side of the vein (NZ) or sporangia in a ring (not NZ), often surrounded by a ring of paraphyses, exindusiate. Sporangia thick-walled, free (not NZ) or fused into synangia (NZ), lacking an annulus and dehiscing by a slit (NZ) or pore (not NZ), maturing ± simultaneously, with 1000s of spores per sporangium. Homosporous; spores monolete (NZ) or trilete (not NZ), granulate or verrucate (NZ) or spiny (not NZ), lacking chlorophyll.

A family of six genera and c. 60 species. The treatment here follows the revision of Marattiaceae by Murdock (2008a) which, in turn, was based on current understanding of the phylogeny of marattioid ferns (Murdock 2008b).

Murdock’s investigation recognised that Marattia, as traditionally defined, was paraphyletic. He split the genus into three morphologically distinct and monophyletic genera: Marattia sens. str., restricted to the Neotropics and Hawai’i; Eupodium, in the Neotropics; and Ptisana, widely distributed in the Palaeotropics from Ascension Island to the Marquesas Islands, extending south to New Zealand.

Species delimitation varies widely in the family, especially in Danaea and Angiopteris. Numbers vary between 17 and c. 60 in Danaea and anything from one polymorphic species to over 200 poorly defined species in Angiopteris (Murdock 2008a). Considerable species-level revision remains to be done in a family that potentially includes many threatened and highly restricted endemic species.

The family name Marattiaceae Kaulf. includes the type of Danaeaceae C.Agardh, and since the latter is an earlier name it has priority over Marattiaceae (Murdock et al. 2006). Pichi Sermolli (1970) suggested that the even earlier name, Marattiaceae Berchtold & Presl (1820), published as "Marattiae", constituted valid publication of the family name. However, a change to the rules of botanical nomenclature in the Vienna Code of 2006 (Art. 18.2, Note 1, Ex. 4) specifically states that "names published at the rank of order ("řad") by Berchtold & Presl (1820) are not to be treated as having been published at the rank of family, since the term family ("čeled") was sometimes used to denote a rank below the rank of order". Since the name Marattiaceae becomes a synonym when that family is defined to include Danaeaceae, Marattiaceae Kaulf. has now been conserved against Danaeaceae C.Agardh.

The Marattiaceae comprises terrestrial ferns characterised by large starchy stipules at the base of the stipe, pulvini on the fronds, sporangia in a double row or ring, or fused laterally into synangia, each opening by a longitudinal slit or pore, and a base chromosome number of 39 or 40.