Turraea bardotiae Lescot & Callm., 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 : 105

Turraea bardotiae Lescot & Callm. , sp. nov.

( Fig. 1 )

DIAGNOSIS. — Turraea bardotiae sp. nov. is distinguished by its large white flowers (4-6 cm long), its exceptionally long and narrow, linear-oblong (8-10 × 1-2 mm) foliaceous calyx lobes, with apparent venation, and by its staminal tube lacking distal appendices.

TYPUS. — Madagascar • Diana Region [Prov. Antsiranana], Matsaborimanga, Réserve Spéciale d’Ankarana , tsingy au-dessus de la grotte du camp des anglais; 12°54’43”S, 49°06’39”E; 180 m; 12.XII.1997; fl.; Bardot-Vaucoulon 1068 (holo-, P [ P00701770 ]!, iso-, G [ G00415937 ]!, K!, MO, P [ P00701771 , P06773979 ]!, TAN). PHENOLOGY. — Flowers in November , fruits in February .

DISTRIBUTION AND ECOLOGY. — Turraea bardotiae sp. nov. is known from the cracks of the limestones in the dry deciduous forests growing on the tingy of the Ankarana massif at an elevation of 180 m. ETYMOLOGY. — The species epithet honours our friend and colleague Martine Bardot-Vaucoulon. Martine collected more than 2000 specimens in the Ankarana massif and studied its vegetation ( Bardot-Vaucoulon 1997). She collected many new species in that limestone massif including two of the three collections known of Turraea bardotiae sp. nov.

CONSERVATION STATUS. — Turraea bardotiae sp. nov. is known only from a single locality in the Ankarana massif. Despite its protection, the massif has seen a zone heavily exploited for sapphire mining and the forest is subject to wild fires ( Goodman et al. 2018). The new species is therefore preliminary assessed as “Critically Endangered” [CR 2ab(iii)] in accordance with IUCN Red List Categories and Criteria ( IUCN 2012).

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • Diana Region [Prov. Antsiranana], Matsaborimanga, Réserve Spéciale d’Ankarana, tsingy au dessus de la grotte du camp des anglais; 12°54’45”S, 49°06’39”E; 180 m; 10.XI.1990; fl.; Bardot-Vaucoulon 273 ( P [ P00701761 ]) • Ankarana RS, close to Camp d’Anglais; 12°33’S, 49°40’E; 180 m; 18.II.1994; Lewis et al. 1140 ( K [ K000469042 ], MO, P [ P06773976 , P06773977 ], TAN) .

DESCRIPTION

Sprawling shrub or small tree, 2-4 m tall, branched at base; twigs with light-brown, striated bark. Leaves unifoliolate; leaf blade obovate to suborbicular, subcoriaceous, tomentose on both sides, (1.5-)3-4(-5) × (1-)1.5-2(-2.5) cm, base obtuse to attenuate, margin entire, sub-revolute sometimes undulate, apex rounded, sometimes slightly attenuate, domatia absent; primary and secondary veins prominent abaxially, slightly visible adaxially; petiole 2-3 mm long, tomentose. Inflorescences pauciflorous, 1-(2) flowers. Flower buds slightly enlarged and obtuse at apex. Flowers 4-6 cm long; pedicel 6-10 mm long, puberulous. Calyx cupuliform, 2 × 3-4 mm, 5-lobed, each lobe extremely developed, foliaceous, linear-oblong, rounded obtuse at the apex, 8-10 × 1-2 mm, with apparent venation, puberulous. Corolla white of 5 spathulate petals, roughly equal to the staminal tube, 35-40 mm long, c. 1.5 mm wide at base, 2 mm wide in the proximal part, pubescent with stiff white hairs, erect and sparse along the entire length, denser towards the apex on the outside. Staminal tube somewhat curved, slightly enlarged distally, 30-35 mm long, puberulous; appendices absent; anthers 10, subsessile, oblong, 1.2 × 0.3 mm, apiculate, apicule c. 0.5 mm, puberulent; ovary subglobose, c. 1 in diam., villose, locules 5, each with 2 collateral ovules; style exserted 5-10 mm, beyond the staminal tube c. 0.3 mm in diam. Receptaculum pollinis clavate, 3 × 1.5 mm; stigma discoid, 0.4 × 1.2 mm. Fruits a capsule, subglobose, c. 8 mm diam., brownish-green, dehiscing by 5 valved, wrinkled, puberulous; pericarp c. 0.2 mm thick; calyx persistent. Seeds centrally grouped, reniform, 4 × 3 mm; testa brownish, smooth; aril present.

NOTES

Turraea bardotiae sp. nov. is very distinctive among the Malagasy Turraea species in its exceptionally long and narrow, linear-oblong foliaceous calyx lobes, with apparent venation ( Fig. 1 ). Only three collections are known in the rather well collected Ankarana massif. This may be explained by its ecology, growing on eroded and lacerated limestones (tsingy) which are difficult to walk on. This species is most likely rare and known only from the tsingy above the cave of the “camp des anglais”.

Figures

FIG. 1. — Turraea bardotiae Lescot & Callm., sp.nov.: A, flowering stem; B, leaf, adaxial surface;C, flower;D, calyx;E, fruit.A-D, Bardot-Vaucoulon 1018; E, Lewis et al. 1140. Drawings: Alain Jouy. Scale bars: A, 4 cm; B, E, 1 cm; C, 15 mm; D, 5 mm.