Turraea vohisandrianensis Callm. & Nusb., 2024

Callmander, Martin W. & Nusbaumer, Louis, 2024, Descriptions of ten new species of Turraea L. (Meliaceae, Turraeeae) from Madagascar with notes on the species described by Buchenau, Adansonia (3) 46 (11), pp. 103-128 : 122

Turraea vohisandrianensis Callm. & Nusb. , sp. nov.

( Fig. 12 )

DIAGNOSIS. — Turraea vohisandrianensis sp. nov. can be distinguished by its small solitary white flowers (1-1.5 cm long) and comparatively long pedicel (5-15 mm) and exserted style (4 mm), its rudimentary bifid appendices, its subglobose receptaculum pollinis, and its glabrous capsules.

TYPUS. — Madagascar • Anosy Region [Prov. Toliara], pentes inférieures du massif du Vohitsiandriana, au sud-ouest de FortDauphin; 100-300 m; [25°10’S, 46°39’E]; 11. I.1963; fl.; Service Forestier 22385 (holo-, P [ P06709140 ]!; iso-, G [ G00413517 ]!, K!, MO, P [ P06709138 , P06709139 ]!, TAN) .

PHENOLOGY. — Flowers and fruits in December to January.

DISTRIBUTION AND ECOLOGY. — Turraea vohisandrianensis sp. nov. appears to be endemic to the dry spiny thicket and transition forests growing on granite in the climatic transition zone between the sub-arid south-west to the more mesic east. The new species is known at an elevation between 100 to c. 200 m.

ETYMOLOGY. — The specific epithet refers to the Vohisandriana mountain where the species seems to be restricted. The mountain name displays some orthographic variants on Humbert and Capuron’s labels, i.e. “Vohitsandriana” “Vohitsiandriana”. The official 1:100 000 map of the Foiben-Taosarintanin’i Madagasikara [FTM, National Cartography Authority of Madagascar, Map M-62 “Ranopiso”] indicates that this mountain near the sea west of Analapetsa is called Vohisandria. This is most likely since the southern language generally omits the “na” ending (Ramahaimandimby, pers. comm.). We follow here the official FTM map and omit the “t” in the epitet reffering to this mountain.

CONSERVATION STATUS. — The new species is restricted to a poorly known mountain west of Tôlanaro and south of Ranopiso,

i.e. the Vohisandriana mountain. Collections from this mountain are known by René Capuron and Henri Humbert (1887-1967) who visited the site together in 1955 during Humbert’nineth travel to the Island. Capuron later visited the site in 1963 and 1968. The forests of this region are threatened by slash-and-burn agriculture and charcoal production ( Goodman et al. 2018). Despite extensive inventories by the Missouri Botanical Garden in the nearby Ambototsirongorongo protected area, this species has not been collected since 1968. With a single locality in a habitat under severe threat, Turraea vohisandrianensis sp. nov. is therefore preliminary assessed as “Critically Endangered” [CR B2ab(iii)] in accordance with IUCN Red List Categories and Criteria ( IUCN 2012).

ADDITIONAL SPECIMEN EXAMINED. — Madagascar • Anosy Region [Prov. Toliara], versant sud et plateau sommital du massif du Vohitsandriana, au sud de Ranopiso; [25°10’S, 46°39’E]; 180 m; 8.XII.1968; fl., fr.; Service Forestier 28580 ( G [ G00642058 ], P [ P00263848 , P00263849 ], TEF) .

DESCRIPTION

Treelet; twigs brownish, glabrous. Leaves unifoliolate; leaf blade chartaceous to subcoriaceous, elliptic, (2-)3-4.5(-5) × (0.6-)1-2(-2.5) cm, base acute, margin entire, undulate, apex attenuated-acuminate, glabrous; adaxial surface bright shiny green; abaxial surface dull pale green; primary vein slightly prominent, secondary veins slightly visible on both surfaces; reticulum discrete; petiole 3-5 mm, glabrous to glabrescent. Inflorescences with solitary flower. Flower buds enlarged and obtuse at the apex. Flowers 1-1.5 cm long; pedicel 5-15 mm long, glabrous. Calyx cupuliform, 2 × 3 mm, 5-lobed, each lobe with an apical linear tooth 1 × 0.2 mm, glabrous to glabrescent outside, glabrous inside. Corolla white, with 5 spatulate petals, longer than the staminal tube, reaching the base of the stigma, 9-11 mm long, 1 mm wide at base, 2 mm wide in the proximal part, glabrous. Staminal tube cylindrical, 6 mm long, glabrous outside, hirsute inside; appendages 10, reduced, each with 2 blades rounded at the top, 1.5 mm short, at the base of each anther, glabrous; anthers 10, subsessile, elliptical-oblong, 0.8 × 0.3 mm, apiculate, apicule c. 0.2 mm long; ovary ovoid, 1 mm in diam., glabrous, locules 5, each with 2 collateral ovules; style exserted, 4 mm long, 0.15 mm in diam. Receptaculum pollinis subglobose, 1.2 mm in diam.; stigma capitate, 1 × 0.2 mm. Fruit a capsule, globose ovoid, greenish, with 4-5 valves, longitudinally striate, glabrous; pericarp 0.2 mm thick; calyx persistent. Seeds centrally grouped, reniform, 4 × 2.5 mm; testa brownish, granular; aril present.

NOTES

Turraea vohisandrianensis sp. nov. is very distinctive among the Malagasy Turraea species by its small solitary flowers and comparatively long exserted style with a subglobose receptaculum pollinis ( Fig. 12 ).

Leroy & Lescot coined this new species under the name “ Turraea breviflora ”. This epithet is already preoccupied in Turraea by T. breviflora Ridl. , an enigmatic species from Penininsular Malaysia now placed in the genus Munronia Wight as M. breviflora (Ridl.) Mabb. & Muellner ( Muellner & Mabberley 2008).

Figures

FIG. 12. — Turraea vohisandrianensis Callm. & Nusb.,sp. nov.: A, flower; B, leaf,adaxial surface;C, fertile stem;A, Service Forestier 22385; B, C, Service Forestier 28580. Drawings: Alain Jouy. Scale bars: A, 4 cm; B, 10 mm; C, 5 mm.