Crepidomanes minutum (Blume) K.Iwats. var. mascarenense Pynee & 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 : 23

10. Crepidomanes minutum (Blume) K.Iwats. var. mascarenense Pynee & Dubuisson ( Pynee et al. 2012: 28), as ‘mascarenensis’, Fig. 10F, G .

Type:— MAURITIUS. Mt. Lagrave, 18 January 1974, D. Lorence s.n. (holotype MAU, MAU 0009282!).

Short description—As the typical variety but displaying dwarf fronds (up to 2.5 cm), mostly flabellate or digitate, and usually no stipe proliferation.

Global distribution—Western Indian Ocean.

Current distribution in Mascarenes— La Réunion, Mauritius.

Ecology—Epiphytic on tree-trunks in lowland rainforests (50–850 m).

Specimens examined.— MAURITIUS. Osterlog Valley, October 2010, Hennequin et al. 340 ( P02432434 ) ; Macabé , October 2010, Hennequin et al. 370 ( MAU 0008233 , P02432404 ) ; Pétrin , June 2016, K. Pynee et al. s.n. ( MAU 0017503 ) ; Without locality, without date, L. Barclay s.n. ( MAU 0009281 ) .

— LA RÉUNION. Le Tremblet, April 2003, J.- Y. Dubuisson HR-2003-5 ( P) ; J.- Y. Dubuisson HR-2003-6 ( P); Basse Vallée-Vallée heureuse, May 2005, J.- Y. Dubuisson HR-2005-6 ( P) .

Note—Originally considered as endemic to the Mascarenes, the lowland populations with dwarf specimens lacking proliferation designating the var. mascarenense are actually observed on all the islands of the western Indian Ocean with lowland rainforests (including the Seychelles and Comores). This reinforces the hypothesis that such populations are lowland ecotypes of a species more often observed in montane rainforests.

Figures

FIGURE 10. A. Crepidomanes inopinatum (Pic.Serm.) J.P.Roux var. inopinatum, as lithophyte (La Réunion, ‘Petite Plaine’). B. C. inopinatum var. tamonii Y.Robert & Dubuisson, habit (Y. Robert 913, P02433924). C. C. minutum (Blume) K.Iwats. var. minutum, as epiphyte (La Réunion, ‘Bébour’). D. C. minutum var. minutum, frond with long terete wingless stipe. E. C. minutum var. minutum, showing stipe proliferation, scale = 1 cm (from Madagascar, F. Rakotondrainibe 3698, P00085267). F. C. minutum var. mascarenense Pynee & Dubuisson, as epiphyte (La Réunion, ‘Grand Etang’). G. C. minutum var. mascarenense, detail of fronds with short stipes. (photographs. A: J.-Y. Dubuisson; C–D: C. Chaussidon; F–G: E. Grangaud).