Crepidomanes inopinatum (Pic.Serm.) J.P.Roux var. tamonii Y. Robert & Dubuisson, 2014

Dubuisson, Jean-Yves, Hennequin, Sabine & Robert, Yannis, 2014, Crepidomanes inopinatum var. tamonii (Hymenophyllaceae), a new lowland variety endemic to semi-dry forests in La Réunion, Phytotaxa 173 (2), pp. 163-167 : 165-166

Crepidomanes inopinatum (Pic.Serm.) J.P.Roux var. tamonii Y. Robert & Dubuisson , var. nov., Fig. 3B

Plants similar to the typical Crepidomanes inopinatum but dwarfed to less than half the regular average size.

Type :— LA REUNION. La Possession, ravine de la Grande Chaloupe, 650 m, August 2006, Y . Robert 913 (holotype P, isotype REU)

Epilithic ferns. Rhizomes creeping, branched, filiform, ca. 0.3 mm thick, densely covered with dark-brown simple hairs, rootless or with root-like shoots covered with the same hairs as those on rhizomes. Fronds 0.2–5.0 cm apart; stipes 0.2–1.0 cm long, winged at least in the upper part, with dark brown hairs mostly concentrated on its basal part and few all along the stipe. Laminae 0.5–3.0 × 0.5–1.5 cm, obovate, flabellate to pinnatifid. Laminar segments linear, ca 0.5 mm wide, with true veins and often longitudinal folds (in dried specimens) at each side of the true vein, simulating veins. Sori 2–6 per fertile frond, on proximal segments; indusia campanulate, 1.0–1.2 × 0.8–1.0 mm, bordered on both sides by laminar cells, forming a wing; mouth of indusia slightly dilated; receptacles short to long-exerted.

Distribution and habitat: —Endemic to La Réunion, epilithic on wet and shady rocks in wet ravines at low to middle elevations (100–900 m) in remaining semi-dry forests. Uncommon. Such ecotypes remain to be checked in equivalent habitats in neighboring islands such as Madagascar or continental Africa.

Worldwide distribution of the species: —The species is distributed from central Africa to the western Indian Ocean.

Etymology: —The varietal epithet is dedicated to the local botanist Jean-Maurice Tamon for his great contribution to the knowledge and preservation of La Réunion flora.

Specimens examined (paratypes): — LA RÉUNION. Vallée de la Grande Chaloupe , La Montagne , 900 m, October 1972, T. Cadet 3810 ( REU 08464); Ravine des Avirons, 650 m, August 2005, E. Grangaud 1688-1; Sentier du Petit Louis, Grand Bassin, 700 m, June 2006, Y. Robert 885; Tampon, sentier Piton Petit Louis vers Grand-Bassin, June 2006, 900 m, Y. Robert 885; Sainte Marie, ravine Kiwi, 500 m, July 2006, Y. Robert 890; Bras Panon, berges de la rivière du Mât, 150 m, July 2009, Y. Robert 1298; Salazie, mare à Poule d‘eau, 700 m, August 2009, Y. Robert 1317; Saint Louis, les Cannots, 650 m, January 2014, Y. Robert 1655; Saint Leu, ravine du Trou, 500 m, December 2005, Tamon & Fontaine s.n.; Sainte Marie, falaise du Cap Soldat, 250 m, October 2007, Tamon s.n.; La Possession, Ilet Solitude, 550 m, december 2007, Tamon s.n; La Possession, Sentier de Dos d‘Ane vers Deux bras, 500 m, March 2010, Tamon s.n .

Note: Except T. Cadet 3810 available in REU and the holotype available at P, all other specimens are available in respective private collections of E. Grangaud, Y. Robert and J.- M. Tamon .

Figures

FIGURE 3. Crepidomanes inopinatum. A. Typical large form occurring in mountainous rainforest (E. Grangaud 1184-1, collected at ‘Rivière des Marsouins, Forêt de Bébour’, 1,320 m). B. Dwarf fertile forms occurring in lowland to midland semi-dry forest (Y. Robert 885, ‘Sentier Piton Petit Louis, Grand Bassin’, 900 m) and corresponding to C. inopinatum var. tamonii. Scale = 1 cm.