Abrodictyum parviflorum (Poir.) Bauret & Dubuisson

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 : 13-14

1. Abrodictyum parviflorum (Poir.) Bauret & Dubuisson ( Dubuisson et al. 2017: 211), Fig. 6

Trichomanes parviflorum Poir. ( Poiret 1808: 83). Type :— MADAGASCAR. Without locality, without date, L.-M.A. du Petit-Thouars s.n. (lectotype P, P00482986 !, here designated; isolectotype P, P00482987 !).

= Trichomanes lanceolatum Poir. ( Poiret 1808: 83). Type :— MADAGASCAR. Without locality, without date, L.-M.A. du Petit-Thouars s.n. (lectotype P, P00482989 !, here designated; isolectotype P, P00482990 !).

= Trichomanes meifolium Bory ex Willd. (Willdenow 1810: 509, 510). ≡ Macroglena meifolia (Bory ex Willd.) Copel. ( Copeland 1938: 83). ≡ Cephalomanes meifolium (Bory ex Willd.) K.Iwats. ( Iwatsuki 1984: 177). ≡ Abrodictyum meifolium (Bory ex. Willd) Ebihara & Dubuisson ( Ebihara et al. 2006: 244). Type:— LA RÉUNION. ‘des bois très élevés à Bourbon’, without date, J.B.G.M. Bory de St.-Vincent 125 (lectotype B, BW 20 201010!, here designated; isolectotype P, P00612303!).

= Trichomanes longisetum Bory ex Willd. (Willdenow 1810: 510, 511). Type:— LA RÉUNION. ‘ Bois de Bourbon’ , without date, J.B.G.M. Bory de St. -Vincent 126 (lectotype B, BW 20 211010!, here designated; isolectotype P, P00064994 !).

= Trichomanes foeniculaceum Bory ex Willd. (Willdenow 1810: 511). Type:—‘ Les Iles de France et de Bourbon. ’, without date, J.B.G.M. Bory de St. -Vincent 127 (lectotype B, BW 20 212010!, here designated; isolectotype P, P00064992 !).

Note—Re-examination of type specimens allowed here to correct and complete information concerning vouchers and locality for some taxa ( T. meifolium , T. longisetum and T. foeniculaceum ) compared to the most recent publications on the subject ( Dubuisson et al. 2017; Dubuisson & Hennequin 2018).

Short description—Terrestrial or lithophytic, less often epiphytic; thick, short and erect rhizomes with robust roots and clustered erect fronds; fronds well stipitate, up to 40 cm long, quite variable, narrowly to widely lanceolate or elliptic, more rarely triangular, plane ( Fig. 6C ) or with a brush-like shape ( Fig. 6B ), tripinnate-pinnatifid, with linear (sub)capillary ultimate segments and a thin lamina not exceeding 3 rows of cells on both sides of the veins ( Fig. 6D ); sori numerous, paratactic, obconic to slightly campanulate, truncated or with a very slightly dilated mouth ( Fig. 6D ); receptacle short to long-exerted.

Global distribution—Western Indian Ocean (excl. Comores).

Current distribution in Mascarenes— La Réunion, Mauritius.

Ecology—Usually terrestrial in the understory of rainforests, occasionally lithophytic, more rarely epiphytic on the base of trunks, often near streams, from low to high elevations (90–2,200 m).

Representative specimens examined— MAURITIUS. Mt Cocotte, October 2010, S. Hennequin et al. 318 (MAU 0008184, P02432374, P02432375).

— LA RÉUNION. Without locality, without date, L.- M. A. du Petit-Thouars s.n. ( P00064996 ) ; Hauts de St Denis , 1833, Goudot s.n. ( P00612302 ) ; without locality, 1834, Bernier 33 ( P00064995 , on the same sheet as the A. meifolium isotype) ; Brûlé de St Denis , 1886, C. Keller s.n. ( P01526528 ) ; Forêt des Makes , May 1947, J. Bosser 11152 ( P01526536 ) ; Saint-Philippe , Forêt de Mare Longue, December 1967, T. Cadet 1183 ( P01526521 ) ; Forêt des Cabris , Plaine des Palmistes, November 1985, K. Kramer et al. 9363 ( P01526512 ) ; Bébour , April 1999, J.- Y. Dubuisson HR-1999-21 ( P), HR-1999-22 ( P) ; Saint-Philippe , Forêt de Mare Longue, April 2002, J.- Y. Dubuisson HR-2002-13 ( P02433295 , mix of plane [left] and brush-like [right] forms) ; Le Tremblet, April 2003, J.- Y. Dubuisson HR 2003-2 ( P, brush-like form), HR 2003-2 ’ ( P, plane form) .

Note—This species was first named A. meifolium and is known under this name in the main floras ( Tardieu-Blot 1951, 2008; Grangaud 2010). This name was traditionally used for the brush-like form while Tardieu-Blot treated the local plane forms as the supposedly distinct Trichomanes parviflorum . Dubuisson et al. (2017) demonstrated that A. meifolium and T. parviflorum belong to a single and highly polymorphic species, hence designating the new combination A. parviflorum as the valid species according to nomenclatural rules.

Figures

FIGURE 6. Abrodictyum parviflorum (Poir.) Bauret & Dubuisson. A. typical habit, here as terrestrial (La Réunion, ‘Mare Longue’). B. Brush-like ‘meifolium’ form (La Réunion, ‘Grand Etang’). C. Plane ‘parviflorum’ form (La Réunion, ‘Grand Etang’). D. Detail of subcapillary ultimate segments and sori (photographs.A: C. Chaussidon; B, D: L. Bauret; C: J.-Y. Dubuisson).