Didymoglossum lorencei (Tardieu) Ebihara & Dubuisson

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 : 15

Didymoglossum lorencei (Tardieu) Ebihara & Dubuisson

Didymoglossum lorencei (Tardieu) Ebihara & Dubuisson in Ebihara et al. , Blumea 51: 236 (2006). –

Trichomanes lorencei Tardieu , Adansonia , sér. 2, 17 (2): 147, pl. 1, t. 7–13 (1977). – Type: Mauritius, D.H. Lorence 1175 (holo-: P00477828!).

Short description

Epiphytic or lithophytic; long-creeping filiform rhizomes, rootless and densely covered by dense black trichomes, bearing widely separated pending fronds; fronds sessile to subsessile, up to 1.5 cm long, oblong to obovate, entire with entire to undulate margins, with palmate venation and false veins parallel to true veins, hairy with dark not pedunculated trichomes on lamina margins; one single terminal sorus per fertile frond, cylindrical with lips usually parallel and with brown margins.

Global distribution

Comoros, Madagascar, Mauritius, La Réunion.

Distribution in Comoros

Mayotte, Mohéli.

Additional specimens examined

COMOROS: MAYOTTE, Mont Tchaourembo à 2.5 km au SE de la ville de Ouangani, 13 Nov. 2002, F.Rakotondrainibe et al. 6688 (P00311404). MOHÉLI, Piste entre Miringoni et le Chalet St Antoine, 4 Nov. 2008, G.Rouhan et al. 874 (P00684865).

Note

Didymoglossum lorencei has simple and entire fronds bearing marginal starred hairs and always a single sorus, while the morphologically close D. robinsonii (Hook. ex Baker) Copel. (presented here-after) has fronds often lobed to pinnatifid (see Fig. 2B ) and often more than one sorus.

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.