Deidamia commersoniana DC., Prodr.

Gautier, Laurent & Callmander, Martin W., 2021, A synoptic revision of the genus Deidamia (Passifloraceae), Candollea 76 (2), pp. 293-297 : 295-296

2. Deidamia commersoniana DC., Prodr. 3: 337. 1828 ( Fig. 1 ).

Lectotypus (designated here): MADAGASCAR: sine loco, s.d., Commerson s.n. (P-JU no 16698 [ P06975621 ]!; isolecto-: G-DC [ G00659428 , G00207194 ]!; P [ P00137326 ]!) .

= Deidamia bipinnata Tul. in Ann. Sci. Nat., Bot. sér. 4, 8: 49. 1857, syn. nov. Lectotypus (designated here): MADAGASCAR. Reg. DIANA [Prov. Antsiranana]: “Nossi-bé au pied du Loucoubé”, VIII.1848, Boivin 2127 ( P [ P00137325 ]!). Syntypus: MAYOTTE: “Montagnes de Moussa Péré”, X.1848, Boivin 3301 ( P [ P00209164 ]!) .

= Deidamia setigera Tul. in Ann. Sci. Nat., Bot. sér. 4, 8: 49. 1857, syn. nov. Lectotypus (designated here): MADAGASCAR: sine loco, 1847 – 1852, Boivin s.n. (P [ P00137328 ]!; isolecto-: P [ P00137327 ]!).

= Modecca membranifolia Baker in J. Linn. Soc., Bot. 25: 317. 1890. Holotypus: MADAGASCAR: “Chiefy from North-West Madagascar”, IX.1897, Baron next5866 (K [ K000311049 ] image!).

[Bardot-Vaucoulon 835] [Picture: © M. Bardot-Vaucoulon]

Distribution and ecology. – Deidamia commersoniana is widely distributed in Madagascar throughout the eastern escarpment, from Marojejy southward to Andohahela NP, as well as in the Highlands, the Sambirano, and in the far North, from sea-level to 1200 m in humid, sub-humid, and dry bioclimatic regions. The species is also found on the island of Mayotte ( Comoros Islands). It is a large liana with the main stem recorded to reach a basal diameter of 10–15 cm ( PERRIER DE LA BÂTHIE, 1945) and to grow up to 8 m high (but likely much higher) in lowland to medium altitude moist evergreen and semi-evergreen forests, often collected in secondary environments and forest margins.

Conservation status. – With an EOO of 489,792 km ² and an AOO of 100 km ² (qualifying for Endangered under criterion B), Deidamia commersoniana is known from 17 locations with respect to the most plausible threat which is habitat destruction for agriculture. However, most of these locations are within the protected area network (Ampasindava, Analamazaotra, Andohahela, Ankarana, Corridor Forestier Ambositra-Vondrozo, Lokobe, Loky Manambato, Montagne d’Ambre, Marojejy, and Tsaratanana) and no decline can be inferred. Furthermore, the species apparently thrives in secondary environments. It is therefore assessed as “Least Concern” [LC] ( IUCN, 2012).

Notes. – CANDOLLE (1828: 337) described Deidamia commersoniana on the basis of an unnumbered Commerson collection. Original material consists of four specimens (two in G-DC, one in P and one in P-JU). The P-JU sheet, annotated in Candolle’s hand “ Deidamia commersoniana DC. ”, is the best-preserved material and is designated here as the lectotype. The original material in G-DC consists of a sheet with sterile material filed under D. commersoniana [G00659428] and another with flowering material under Crateva obovata Vahl [G00207194]. A note on G00659428 in Candolle’s hand “ces feuilles qui me paraissent celles d’un Bignonia ou d’un Deidamia étaient mélangées et entortillées avec le Crateva obovata sans y adhérer [these leaves which seem to me to be those of a Bignonia or a Deidamia were mixed and twisted with the Crateva obovata without adhering to it]” testifies that the two collections in G-DC were received as a single specimen, probably under the name Crateva obovata . Candolle separated the leaf material that could clearly not belong to any Crateva and filed it under Deidamia commersoniana , whereas he kept the poor flowering material under Crateva obovata . However, the flowers clearly belong to Deidamia commersoniana and we therefore consider both G00207194 and G00659428 as part of original material of this species.

We consider Deidamia bipinnata to be a synonym of D. commersoniana . TULASNE (1857: 50) already noticed the evident similarities between the two taxa and differentiated his new species by the presence of occasional bipinnate leaves, an unreliable character as these two forms of leaves are often found on the same specimen. PERRIER DE LA BÂTHIE (1940: 63) also questioned the morphological differences between these two taxa but maintained them as distinct in his treatment. Deidamia bipinnata was described on the basis of two syntypes and the best-preserved specimen in P, Boivin 2127, is designated here as the lectotype.

Deidamia setigera was described on a sterile unnumbered Boivin collection. TULASNE (1857: 50) distinguished it from his D. bipinnata by the presence of two small flagella on the margins of the proximal part of some of the leaflets. Another sterile collection from Mayotte (Barthelat 1295) is the only other specimen that displays such flagella, and this character has not been observed on a fertile specimen. We are convinced it is a character of juvenile individuals, possibly to enhance prehensility during its early development stages, and in later stages of growth the flagella are replaced by marginal glands. As the leaves of these two specimens match the widespread D. commersoniana in all other aspects, we consider D. setigera as a synonym of this species.

Figures

Fig. 1. – Flowers of Deidamia commersoniana DC.