Hymenophyllum sibthorpioides (Bory ex Willd.) Mett. ex Kuhn

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 : 21

Hymenophyllum sibthorpioides (Bory ex Willd.) Mett. ex Kuhn

Hymenophyllum sibthorpioides (Bory ex Willd.) Mett. ex Kuhn, Filices Africanae : 41 (1868). –

Trichomanes sibthorpioides Bory ex Willd. , Species plantarum: 498 (1810). – Type: ‘Habitat in insula Borboniae’, J.B.G.M. Bory de St.­Vincent s.n. (holo-: BW20204010!; iso-: P00612300!).

Trichomanes parvulum Poir., Encyclopédie méthodique, Botanique 8: 64 (1808), non Copel. (1933: 145), nec auct. – Type: ‘L’île de Madagascar’, L.­M.A. du Petit­Thouars s.n. (holo-: P00065014!; iso-: P00065015!).

Microtrichomanes parvulum (Poir.) Copel., The Philippine Journal of Science 67: 37 (1938).

Trichomanes flabellatum Bory ex Desv., Mémoires de la Société linnéenne de Paris 6 (2): 325 (1827), nom. nud. – Type: Cites Trichomanes flabellula d’Urv., Mémoires de la Société linnéenne de Paris 4: 597 (1824).

Trichomanes thouarsianum C.Presl, Eine botanische Abhandlung: 40 (1843). – Type: ‘Habitat in insula Borbonia’, L.­M.A. du Petit­Thouars s.n. (not located).

Hymenophyllum palmatum Bosch, Nederlandsch Kruidkundig Archief 4: 385 (1858). – Type: ‘L’île Bourbon’, s.d., s. coll. s.n. (iso-: K000435612!).

Short description

Epiphytic; long-creeping filiform rhizomes, bearing sparsely distributed roots and long reddish brown trichomes, and widely separated fronds; fronds with wingless stipes, up to 4 cm long, slightly curled in the wild, flabellate to reniform, palmatisect with dichotomous venation; few sori, paratactic, bilabiate without a developed base and with toothed margins.

Global distribution

Western Indian Ocean, East and South Africa.

Distribution in Comoros

Anjouan, Grande Comore, Mohéli.

Additional specimens examined

COMOROS: ANJOUAN, s. loc., 1905?, M.Lavanchie s.n. (P01430258, P00139617); Au camp de base du Mont N’Tringi, en montant vers la crête nord, 14 Nov. 2009, G.Viscardi et al. 166 (P02439808). GRANDE COMORE, Massif du Karthala, 2 Dec. 2002, F.Rakotondrainibe et al. 6872 (P00312335). MOHÉLI, Piste entre Miringoni et le Chalet St Antoine, 4 Nov. 2008, G.Rouhan et al. 888 (P02439806); Au-dessus de Drondroni, 27 Mar. 2011, E.Bidault et al. 65 (P02439771).

Note

The type of the species (J.B.G.M. Bory de St.­Vincent s.n.; BW20204010) is cited from Bourbon (‘ Habitat in insula Borboniae ’; Bourbon is a former name for La Réunion) in the original description by Willdenow (1810) while the type specimen present at P would have been collected in ‘ Ile de France ’ (former name for Mauritius). Three distinct specimens are in fact on the same sheet: the first (P00612300) is thus from Ile de France (Mauritius) while the two others (P00612301 and P00065013) are from Bourbon (La Réunion). Without a precise reading of all the original notes on the sheet, it is easy to consider that all the specimens come from La Réunion. In the 19th century, many plants collected in Mauritius were first transferred to Bourbon before being sent to Europe and this could explain potential confusion. On the sheet present at P, it is clearly indicated that the Mauritian specimen has been sent to Willdenow who published in 1810 the name Trichomanes sibthorpioides . If the type corresponds well to the Berlin specimen, its real origin (La Réunion or Mauritius) remains ambiguous and questionable.