Ptisana fraxinea (Sm.) Murdock (2008b: 746)

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 : 70

Ptisana fraxinea (Sm.) Murdock (2008b: 746) .

Maratttia fraxinea Smith (1790 : t. 48).

Type:— MAURITIUS. Without locality, without date, Thouin 91 (holotype LINN! , possible isotype G ).

Myriotheca fraxinifolia Bory (1804: 266) . Type:— LA RÉUNION. Quartier de Ste. Rose , without date, J.B.G.M. Bory de St Vincent s.n. (holotype P-00466550!, isotype FI, possible isotype K!).

Myriotheca sorbifolia Bory (1804: 267) . Type:— LA RÉUNION. Habitation Fabien sur les hauteurs de St. Denis , without date, J.B.G.M. Bory de St Vincent s.n. (holotype: P-00466549!, isotypes B, FI).

Marattia macrophylla de Vriese in Vriese & Harting (1853: 3). Lectotype (designated by Pichi Sermolli 1969):— MAURITIUS. Without locality, without date, Bojer s.n. (K!).

Marattia cuneiformis de Vriese in Vriese & Harting (1853: 7). Type:— LA RÉUNION. Without locality, without date, s.c. no. 21 (possible type K!, 2 sheets).

Marattia microcarpa Mett. ex Ettingshausen (1864: 246) . Lectotype (designated by Pichi Sermolli 1969):— MADAGASCAR. Nosy-Be [Nossibe], 1846–1848, Boivin s.n. (W, fragment and photo BM!)

Marattia salicifolia auct. non Schrader (1818: 920), sensu Tardieu-Blot (1951), see H. Humbert 3211 (P-01647489!).

After reviewing specimens and literature, we conclude that Ptisana fraxinea does not reach mainland Africa but is restricted to the islands of the Western Indian Ocean. The presence of Ptisana fraxinea (as defined here) in Sri Lanka (as Marattia calliodous de Vriese in Vriese & Harting (1853: 6), Gardner s.n., holotype: K!) is possible but unlikely and should be confirmed on the basis of field work. Since most descriptions available for P. fraxinea are doubtful or fragmentary, we considered specimens from Madagascar, Mauritius, La Réunion and Mayotte, which were accompanied with good descriptions of key characters (see mostly specimens T. Cadet 3598, F. Badré 879, K.U. Kramer 9277, H. Tuyguy 1082, J.-N. Labat 2749, G. Rouhan 338, 1206). These plants have pinnae similar to those of P. fraxinea , as circumscribed above, and are characterized by leaves of up to 2.2(–3.0) m long, with petioles 0.8–1.8 m long (most often longer than the lamina to occasionally slightly shorter), and 2–4 pairs of pinnae, up to 6(–7) pairs for some of the largest leaves only. These characters indicate the morphological affinity with P. laboudalloniana and P. purpurascens , which is also confirmed by our molecular data. On the contrary, the plants from Ethiopia called M. fraxinea by Pichi-Sermolli (1969) are described as being always larger plants, with the petioles typically shorter than the laminae and with a more massive rhizome, so that “this fern resembles Angiopteris sp. ” (see Pichi-Sermolli 1969: 348). Although the pinnae are very similar, their shape and apices of pinnules are slightly different. Therefore , we think that Pichi-Sermolli (1969), in his otherwise excellent revision, misapplied the name Marattia fraxinea in Ethiopia, because he focused on characters of pinnae and probably because he had not been able to observe living specimens from the Mascarenes. This idea is supported by the fact that Pichi-Sermolli (1969), who extensively studied specimens from Ethiopia to South Africa, considered his M. fraxinea as being a very close but distinct species to the South African plants, i.e. Marattia salicifolia , which indeed have the same leaf characteristics, but are not closely related to true Ptisana fraxinea , based on our molecular phylogenetic results. Therefore , we conclude that M. salicifolia is an independent species and that the Ethiopian plant cannot be associated with the name Ptisana fraxinea . The East African Ptisana is very similar to some specimens from Guinea, which we discuss below (see Ptisana sp. A ).

Selected specimens examined:— LA RÉUNION (F. Badré 879, P-01592037; T. Cadet 3598, P-01592042; 4526, P-01592038; K.U. Kramer 9277, P-01592049), MADAGASCAR (T. Janssen et al. 2529, P-00590721; Ms. Marie 55 ex Herb. Paris, K!; Razafitsalama 1151, P!; F. Rakotondrainibe 1281, P-00064683; 4823, P-00134961; Rouhan et al. 338, P-00749288; 1206, P-02432738; s. coll. s.n., labeled “ oppositifolia ”, MO-1854058), MAYOTTE (as M. microcarpa: Pichi Sermolli 1969 ; J.-N. Labat 2749, P-00052881; H. Tuiguy 1082, P-00144987, P-00144988, P-00144989).

Distribution: — Mauritius, La Réunion, Madagascar, Mayotte (as Marattia microcarpa: Pichi Sermolli 1969 ) and the Comoros (as M. microcarpa: Pichi Sermolli 1969 )