Socratina keraudreniana Balle in Adansonia ser. 2, 4: 135. 1964 .

Typus: MADAGASCAR. Prov.Toliara: Gorges du Fiherenana, entre Beanty et Anjamala, [22°57’S 44°19’E], 30- 300 m, I.1947, fl., Humbert 19902 (holo-: P [P05447658]!; iso-: [P05447656, P05447657, P05447660, P05447661]!).

Conservation status. – With an EOO of 34,514 Km², and an AOO of 108 km ² and nine subpopulations, two of which are within the protected area network (Beza Mahafaly and Tsimanampetsotsa) and one occurs in a proposed protected area which currently benefits from only temporary protection (Mikea Forest), S. keraudreniana is assigned a preliminary status of Least Concern (LC) following IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. – Socratina keraudreniana is unique in the genus in having the corolla tube not splitting unilaterally at anthesis but rather divided into five lobes in the distal part only, thus the tube is much longer than the corolla lobes (BALLE, 1964a; Fig. 2 A). The species is known from the south-western part of Madagascar in dry deciduous forests and xerophyte scrub, sometimes on limestone. Despite being a rather widely collected species, only two different hosts have been documented: Grewia sp. ( Malvaceae) (Du Puy & al. 699) and Mimosa delicatula Baill. (Leguminosae) (Phillipson 2595) .

Additional material examined. – MADAGASCAR. Prov. Toliara: Ampanihy vers la Linta, 24°53’S 44°23’E, I.1999, fl., Allorge 2304 (P [P00156506]); 30 km de Tuléar, [23°16’S 44°00’E], II.1962, fr., Bosser 15660 (MO, P [P 05447665, P 05447666], TAN); ca. 2 km N of Itampolo on route to Lavavolo, 10 m, 24°39’S 43°58’E, 8.II.1990, fl., Du Puy & al. 630 (K, P [P 00075257], TAN); Forest of Mikea c. 3 km N of Beroroha, 60 m, 22°52’54”S 43°33’25”E, 8.II.1990, fl., Du Puy, Labat & Comtet 699 (K, P [P016795], TAN); Env. Lac Tsimanampetsotsa (SO), 30 m, [24°07’30”S 43°47’00”E], 24.XI.1960, fl., Leandri & Saboureau 4023 (P [P05447651, P 05447654]); Env. Lac Tsimanampetsotsa (SO), 30 m, [24°07’30”S 43°47’00”E], 24.XI.1960, fl., Leandri & Saboureau 4034 (P [P05447652]); 40 km au env. de Tuléar, 300 m, [23°10’S 44°04’E], II.1962, fl., Keraudren 1368 (P [P05447662]); Fiherena, [22°57’30”S 44°19’00”E], 8.XII.1967, fl., Koechlin 10 (P [P05447663]); Beza Mahafaly RS, 160 m, 23°40’S 44°36’E, 19.XI.1987, fl., Phillipson 2595 (MO, P [P05447653], TAN); Betaimboraky, 120 m, 22°44’12”S 43°31’17”E, 11.XI.1998, fl., Rakotomalaza & Messmer 1816 (G, MO, P [P0544 7655]); Forêt de Mikea, axe Belo-Ankilimihavotse, 0-50 m, 22°05’S 43°22’E, 30.I.2000, fl., Ranaivojaona & al. 280 (MO, P [P05447543], TAN); Makay, forêt Akolitsika, 238 m, 21°40’04”S 44°59’45”E, 2 2.I.2011, buds, Razakamalala 6136 (MO, P, TAN).