Turraea gracilifolia 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 : 109-111

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

( Fig. 4 )

DIAGNOSIS. — Turraea gracilifolia sp. nov. is distingued by its broadly elliptic acuminate leaf blades that are thin, membranous with domatia in the axils of primary and secondary veins and by its pauciflorous inflorescences with 1-2 large red to fuchsia flowers (4-5 cm long). TYPUS. — Madagascar • Diana Region [Prov. Antsiranana], Ankarana, close to Camp d’Anglais ; 12°54’43”S, 49°06’39”E; 180 m; 18.II.1994; fl., fr.; Lewis et al. 1135 (holo-, G [ G00415935 ]!; iso-, K [ K00159881 ]!, MO [MO-3188802] image!, P [ P06801919 ]!, TAN, WAG!) .

PHENOLOGY. — Flowers in January ; fruits in January and March. DISTRIBUTION AND ECOLOGY. — Turraea gracilifolia sp. nov. appears to be endemic to the northern dry deciduous forests of Madagascar at an elevation between c. 100 to 400 m.

ETYMOLOGY. — The specific epithet refers to the slender and delicate leaves of this species.

CONSERVATION STATUS. — The new species is known from eight localities, six of which are situated within the Ankarana protected area. Despite its protection, the massif has seen a zone of heavily exploited for sapphire mining and the forest is subject to wild fires ( Goodman et al. 2018). Based on an EOO of 437 km ², an AOO of 28 km ² and serious plausible threats on its habitat, Turraea gracilifolia sp. nov. is therefore preliminary assessed as “Vulnerable” [VU B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)] in accordance with IUCN Red List Categories and Criteria ( IUCN 2012).

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • Diana Region [Prov. Antsiranana], Anivorano Nord, route d’Ambilobe , km 87, forêt d’Analamahitsy ; [12°50’10”S, 49°13’42”E]; 27.I.1960; fr.; Cours 5492 ( P [ P06801922 ]) • Ankarana, near Campement des Anglais; 12°50’47”S, 49°06’18”E; 82 m; 14. I.2002; fl.; De Block et al. 1228 ( BR, MO [MO-3188629], P [ P04756245 ], TAN) • Forêt de Ambatomamo au sud d’Anivorano Nord : [12°51’S, 49°15’E]; 30. I.1960; fr.; Humbert 32363 ( MO, P [ P06801918 , P06801923 ], TAN) • Forêt de Marovato, Anivorano Nord ; [12°48’S, 49°14’E]; Humbert 32391 ( P [ P06801920 ]) • Ankarana RS, near Campement des Anglais, along path to Matsaborimanga ; 12°54’S, 49°08’E; imm. fr.; Leeuwenberg et al. 14380 ( G, P [ P00536589 ], TAN, WAG [ WAG0089003 ]) • Cañyon de l’Ankarana de Diego ; [12°54’45”S, 49°06’39”E]; I.1969; fl.; Morat 3092 ( P [ P06801908 , P06801909 ]) • Sommet de la Falaise, Ankarana de Diégo ; [12°56’30”S, 49°07’12”E]; I.1969; fl.; Morat 3106 ( P [ P06801915 ]) • Forêt d’Analandriana, au nord de Sakaramy ; [12°25’S, 49°16’E]; 300 m; 14.II.1962; fr.; Service Forestier 20958 ( P [ P06801911 , P06801914 , P06801917 ]) • Forêt d’Analamahitsy, entre Anivorano-Nord et Ambondromifehy (PK 84 de la route DiégoAmbilobe ); [12°50’10”S, 49°13’42”E]; 16.II.1962; fr.; Service Forestier 22022 ( P [ P06801913 , P06801916 ]) • Massif forestier au sud-ouest de Marotaolana, Anivorano-Nord ; [12°48’S, 49°14’E]; 3 and 6.III.1964; fr.; Service Forestier 23346 ( MO, P [ P06801910 , P06801912 ]) .

DESCRIPTION

Treelet to 7 m; twigs light-brown, striated, glabrous. Leaves unifoliolate; leaf blade very thin, membranous, broadly elliptic, glabrous to puberulent, (3-)4-7(-9) × (1.5-)2-3(-4) cm, base acute, margin entire, apex acuminate, sometimes attenuate, adaxial surface dark green, abaxial surface pale green, domatia present in axils of primary and secondary veins; primary vein prominent, secondary veins slightly visible adaxially, prominent abaxially with reticulum visible; petiole 1-3 cm, glabrous to glabrescent. Inflorescences pauciflorous, 1-2 flowers. Flower buds slightly dilated and obtuse at the apex. Flowers 4-5 cm long, pedicel 8-15 mm long, glabrous. Calyx cupuliform, green, 2 × 3-4 mm, 5-lobed, each lobe with a short apical tooth c. 0.5 mm long, pubescent on margins, puberulent on both sides. Corolla red to fuchsia, 5 petals, roughly equal to the staminal tube, 35-40 mm long, 1.5 mm wide at base, c. 2 mm wide in the proximal part, glabrous, puberulent distally outside, glabrous on the inside. Staminal tube cylindrical, glabrous outside, papillose and with large papillae towards the apex, hairy with scattered bright white hairs inside; appendages absent; anthers 10, yellow, elliptic, 2.8 × 0.4 mm, apiculate. Ovary subglobose, 1 mm in diam., villose with bright yellow-white hairs, locules 5 with 2 collateral ovules; style exserted 2-5 mm beyond the staminal tube, c. 0.3 mm in diam. Receptaculum pollinis ellipsoid, 2.8 × 0.5 mm; stigma discoid, 0.3 × 0.8 mm. Fruits a capsule, subglobose, 10-12 mm in diam., pale green, dehiscing by (8-)10 valves; pericarp 0.2 mm thick; calyx persistent. Seeds 4-7, centrally grouped, reniform, 0.4 × 0.2 mm; testa smooth, shiny, aril present.

A E C D B

NOTES

Turraea gracilifolia sp. nov. is characteristic among the Malagasy Turraea species by its thin, and membranous leaf blades bearing domatia and by its pauciflorous inflorescences with 1-2 large red to fuchsia flowers.

This species has been identified by several unpublished names before its description above. The collection Service Forestier bears the unpublished name “ Turraea diegoensis ” in Leroy’s hand and “ Turraea anivoranensis ” in Capuron’s hand while the name “ Turraea moratii ” appears in the unpublished treatement by Leroy & Lescot.

Figures

FIG. 4. — Turraea gracilifolia Callm. & Nusb., sp. nov.: A, fruiting stem; B, leaf, adaxial surface; C, D, fruit; E, flower; A-C, Service Forestier 22022; D, Cours 5492; E, Lewis et al. 1135. Drawings: Alain Jouy. Scale bars: A, 4 cm; B, E, 20 mm; C, 5 mm; D, 10 mm.