Ptisana robusta (Alston) Senterre & Rouhan, 2014

Senterre, Bruno, Rouhan, Germinal, Fabre, Isabelle, Morel, Charles & Christenhusz, Maarten J. M., 2014, Revision of the fern family Marattiaceae in the Seychelles with two new species and a discussion of the African Ptisana fraxinea complex., Phytotaxa 158 (1), pp. 57-75 : 71

Ptisana robusta (Alston) Senterre & Rouhan , comb. nov.

Marattia robusta Alston in Exell (1956: 8). Ptisana fraxinea var. robusta (Alston) Murdock (2008b: 746) .

Type:— SÃO TOMÉ. Monte Café, 1200 m, 17 January1949, J.V.G. Espírito Santo 191 (holotype BM! , isotypes COI , LIS-C000002 ! ).

Ptisana robusta is a large plant (about same size as Seychelles plants, i.e. P. laboudalloniana ), with sessile, symmetrical pinnules and a remarkably prickly pinna rachis. The conclusions made by Pichi Sermolli (1969) regarding the affinities between Marattia robusta and M. fraxinea (as M. macrophylla ), as well as confusions between M. fraxinea and M. salicifolia , can be explained by the importance given to pinnules width, which we think should only be considered as a secondary character.

Distribution: —Endemic to São Tomé.