Vandenboschia gigantea (Bory ex Willd.) Pic.Serm.

Dubuisson, Jean-Yves, Pechon, Timothée Le, Bauret, Lucie, Rouhan, Germinal, Reeb, Catherine, Boucheron-Dubuisson, Elodie, Selosse, Marc-André, Chaussidon, Cécile, Dajoz, Isabelle, Pynee, Kersley, Grangaud, Edmond, Robert, Yannis, Tamon, Jean- Maurice & Hennequin, Sabine, 2018, Disentangling the diversity and taxonomy of Hymenophyllaceae (Hymenophyllales, Polypodiidae) in the Mascarene archipelago, with ecological implications, Phytotaxa 375 (1), pp. 1-58 : 40

26. Vandenboschia gigantea (Bory ex Willd.) Pic.Serm. ( Pichi Sermolli 1968: 197), Fig. 18C–E

Trichomanes giganteum Bory ex Willd. (Willdenow 1810: 514, 515). ≡ Trichomanes radicans Sw. ( Swartz 1800: 97) var. gigantea (Bory ex Willd.) Mett. ex Kuhn ( Kuhn 1868: 36). Type:—‘Ile Mascareigne’, without date, J.B.G.M. Bory de St.-Vincent 122 (lectotype B, BW 20 216010!, here designated; isolectotype P, P00477826!).

Short description—Terrestrial and climbing; long-creeping thick rhizomes with robust roots (especially on terrestrial parts), bearing widely separated erect to pending fronds; fronds stipitate, up to 60 cm long, lanceolate to ovate, bipinnate-pinnatifid to tripinnate-pinnatifid or more divided; numerous sori, paratactic, cylindrical to obconic with truncated mouth; receptacle short to long-exerted.

Global distribution— Comores, Madagascar, La Réunion.

Current distribution in Mascarenes— La Réunion.

Ecology—Hemiepiphytic in lowland to montane rainforests (450–1,500 m). The plant first colonizes a wide surface of soil in the understory ( Fig. 18D ), and then is able to secondarily climb onto tree-trunks (as also detailed in Dubuisson et al. 2003).

Specimens examined— MAURITIUS. Without locality, without date, sine collector (MAU 2079); without locality, without date, sine collector (P01526230); without locality, without date, sine collector (P01526238); without locality, without date (likely 19th century), C. Meller s.n. (MAU 2080); witout locality, 1868, C. Meller s.n. (P01526229).

— LA RÉUNION. Without locality, 1848, M. Boivin s.n. ( P01430213 ) ; Bébour , August 1971, (collected by M. Sauvage) R. Hébant 121 ( P) ; Takamaka , July 1991, D. Lorence 6946 ( MAU 22068 ) ; Forêt de Mare Longue , April 2002, J.- Y. Dubuisson HR 2002-14 ( P02433296 ) .

Note—This species is known only from a few old specimens (from the 19 th century) in the Mauritian collections, but has not recently been observed on Mauritius, and hence we decided not to report it from the island.

Figures

FIGURE 18. A. Polyphlebium diaphanum (Kunth) Ebihara & Dubuisson, as epiphyte (La Réunion, ‘Forêt de Bon Accueil, Les Makes’). B. P. diaphanum, detail of a frond and sori. C. Vandenboschia gigantea (Bory ex Willd.) Pic.Serm., climbing on a tree trunk (La Réunion, ‘Mare Longue’). D. V. gigantea, terrestrial parts (La Réunion, ‘Grand Etang’). E. V. gigantea, detail of a long-creeping climbing rhizome (photographs.A: L. Bauret; B–E: J.-Y. Dubuisson).