Socratina bemarivensis (Lecomte) Balle in Adansonia ser. 2, 4: 135. 1964

Callmander, M. W., I. Luino, S. Da-Giau, C. Rakotovao & L. Gautier, 2014, A synoptic revision of the Malagasy endemic genus Socratina Balle (Loranthaceae)., Candollea 69 (1), pp. 65-73 : 66-68

Socratina bemarivensis (Lecomte) Balle in Adansonia ser. 2, 4: 135. 1964 .

÷ Loranthus bemarivensis Lecomte in Not. Syst. (Paris) 4: 37. 1923 . ÷ Tapinanthus bemarivensis (Lecomte) Danser in Verh. Kon. Akad. Wetensch., Afd.Natuurk., sect. 2. 29: 108. 1933 .

Lectotypus (designed by BALLE, 1964b: 135): MADAGASCAR. Prov. Mahajanga: Bois de la Haute Bemarivo, [16°06’S 47°44’E], XI.1918, fl., Perrier de la Bâthie 10646 ( P [ P00573453 ]!; isolecto-: P [ P0573454 , P0573455 ]!).

Conservation status. – With an EOO of 2,336 km ², and an AOO of 27 km ² and three subpopulations, none situated within the protected area network, S. bemarivensis is assigned a preliminary status of “Vulnerable” [VU B1ab(i)+2ab(i)] following IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes. – Socratina bemarivensis was originally described in Loranthus Jacq. by LECOMTE (1923) following the very broad generic concept of ENGLER & KRAUSE (1935), a genus that is now circumscribed as mostly restricted to temperate or mountain forest from Europe to south-est Asia ( BARLOW, 1997). Henri Perrier de la Bâthie, who collected both syntypes wrote on the label of one of them (Perrier de la Bâthie 10652), that the flowers open at maturity with only one longitudinal split along the entire length of the corolla lobes (see BALLE, 1964b: 137). Anthesis of S. bemarivensis is very different to that of Socratina keraudreniana where the corolla divides into five lobes in the distal part ( Fig. 2 ). Several other characters of the morphology of its leaves and flowers allow to differentiate those two species: limb sub-orbicular to largely ovate, 0.8-4.8 cm in width in S. bemarivensis (vs. oblanceolate to obovate, 0.3-0.8 cm in S. keraudreniana ); corolla broad, covered with long (2-2.5 mm) trichomes forming dense indument (vs. corolla slender covered by short (1-1.5 mm) trichomes forming a sparse indument) ( Fig. 2 ).

Perrier de la Bâthie noted several hosts for Socratina bemarivensis: Acacia sp. and Dalbergia sp. (Leguminosae), Eugenia sp. ( Myrtaceae ) and Vernonia sp. ( Asteraceae ) ( BALLE, 1964b). Most Loranthaceae species seem to have a wide range of hosts ( POLHILL & WIENS, 1998) but some species have also very restricted hosts such as Taxillus wiensii known only to grow on Cynometra webberi Baker f. (Leguminosae) ( POLHILL & WIENS, 1998). Further studies are needed in Madagascar to determine if the genus Socratina has host specificity as this information is recorded on very few collections (see also comments under S. keraudreniana ).

Additional material examined. – MADAGASCAR. Prov.Antsiranana: Ambilobe, Ambakirano , Behefaka , Anjahana , forêt d’Ampivanana , 9 km au S de Behefaka, 13°21’12”S 49°09’11”E, 276 m, 6.V.2005, fl. & fr., Ratovoson 105 ( CNARP, MO, P [ P06714072 ], TAN). Prov. Mahajanga: Bord de l’Anovilava, affluent du Bemarivo ( Boïna ), [16°09’S 47°51’E], VI.1906, fl., Perrier de la Bâthie 10642 ( P [ P 05447659, P 05447668, P 05447669] [syntypes]!)

Figures

Fig. 2. – Living plants. A. Socratina keraudreniana Balle; B. S. bemarivensis (Lecomte) Balle; C. S. phillipsoniana Callm. & Luino. [Photos: A: J. Bosser; B: F. Ratovoson; C: I. Luino]