Hymenophyllum Sm. ( Smith 1793 )

Ahamada H. Saïd, Sabine Hennequin, Germinal Rouhan & Jean-Yves Dubuisson, 2017, Disentangling the diversity and taxonomy of Hymenophyllaceae (Hymenophyllales, Polypodiidae) in the Comoros, European Journal of Taxonomy 313, pp. 1-53 : 20

Genus Hymenophyllum Sm. ( Smith 1793)

This pantropical genus (in addition to numerous species in wet temperate areas, especially in southern hemisphere) regroups more than 300 epiphytic (more rarely lithophytic), dwarf to large species with mostly long-creeping filiform rhizomes bearing sparsely distributed roots and pending dissected fronds in addition to sori without developed tubular base (at least for species of the region; Fig. 2A, F ). In the Comoros, species belong to three subgenera following Ebihara et al. (2006): Hymenophyllum , Sphaerocionium (C.Presl) C.Chr. and Mecodium C.Presl ex Copel.

Figures

Fig. 2. Illustration of representative descriptors and states used in the Xper database (see Appendix 1). A. Hymenophyllum hirsutum (L.) Sw., typical bilabiate sori (S) without a developed base, fully hairy lamina with pedunculated brown trichomes (see inset). B. Didymoglossum robinsonii (Hook. ex Baker) Copel., false veins (FV) parallel but not connected to true veins (TV) and marginal dark trichomes clustered here by 6 (see inset). C. Crepidomanes inopinatum (Pic. Serm.) J. P. Roux, typical trichomanoid sori (S) with a developed tubular base, lips are here dilated as a collar. D. Didymoglossum rotundifolium (Bonap.) J. P. Roux, false veins (FV) parallel but not connected to true veins (TV) and continuous submarginal false vein (smFV), here the one-cell thick lamina appears well translucent. E. Crepidomanes bipunctatum (Poir.) Copel., false veins more or less continuous and parallel to margins (mFV) and not connected to true veins (TV). F. Hymenophyllum sibthorpioides (Bory ex Willd.) Mett. ex Kuhn, bilabiate sori (S) with toothed margins. Photographs by A. H. Saïd.