Didymoglossum Desv. ( Desvaux 1827 )

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 : 14

Genus Didymoglossum Desv. ( Desvaux 1827)

The most diversified genus in the archipelago (7 spp.) is pantropical and clusters more than 30 species which are epiphytic or lithophytic, minute to medium-sized with long-creeping and rootless rhizomes bearing fronds that are usually entire to lobed and in some cases pinnatifid (rarely bi-pinnatifid to bipinnate). The laminae exhibit false veins parallel to true veins, at least for the Comorian species ( Fig. 2B, 2D ). The two described subgenera Didymoglossum and Microgonium (C.Presl) Ebihara & K.Iwats. are represented in the Comoros by three and four species, respectively.

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.