Noronhia greeniana

Hong-Wa, Cynthia, 2016, A taxonomic revision of the genus Noronhia Stadtm. ex Thouars (Oleaceae) in Madagascar and the Comoro Islands, Boissiera 70, pp. 1-292 : 119-121

32. Noronhia greeniana Hong-Wa, spec. nova ( Fig. 22D , 23 ).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA, Diégo II, Ramena, Andavakoera, Montagne des Français aux env. du Fort, 12°19’18’’S 49°20’16’’E, 270 m, 29.XII.2008, Hong-Wa 549 (holo-: MO-6615558!; iso-: P!, TAN!) .

Diagnosis

Noronhia greeniana Hong-Wa can be distinguished from other congeneric species by its somewhat tortuous habit, its oblate leaf blades and its solitary, punctate and rostellate fruits.

Description

Trees to 8 m tall, trunk to 20 cm in diam.; young twigs cylindrical, 0.6-1.2 mm in diam., glabrous; bark light gray, rugose. Leaves opposite, semi-deciduous; bud scales rarely persistent; blades light green above and below, oblate, 2.5-3.5 3 1.5-3 cm, subcoriaceous, glabrous, domatia common, base attenuate, margin flat, apex shortly cuspidate, the cusp 0.5-2 mm long, midrib slightly sunken above, distinctly raised above, secondary veins barely visible, 5-8 per side, 4-9 mm apart, looping 1.5-3 mm from the margin; petiole yellowish, 4-7 3 0.7-1 mm, not woody, glabrous. Flowers unseen, but fruits solitary. Fruiting pedicel 1-6 3 1-3 mm; young fruits green, purplish when mature, ovoid, 16-23 3 10-15 mm, surface covered with white dots, apex rostellate, the rostellum slightly flattened, ridged, truncate, with the persistent style; dry pericarp 0.9-1.6 mm thick; endocarp woody; seed 9-14.5 3 5-9 mm.

Etymology

This name honors the late Peter S. Green, who was a Keeper and Deputy Director at the Royal Botanic Gardens, Kew for his contribution to the knowledge of the Malagasy Oleaceae and the olive family in general, most of which he completed after his retirement in 1982 until his passing in 2009.

Distribution, ecology and phenology

Noronhia greeniana occurs in low-elevation dry forests on sandstones and basement rocks in the north, from Montagne des Français to Daraina ( Fig. 19 ). It fruits from September to December.

Conservation status

Noronhia greeniana is currently known only from four collections representing four localities and has an EOO of 765 km 2, an AOO of 16 km 2, and four subpopulations representing three locations, of which two occur within the network of protected areas (Loky-Manambato and Montagne des Français). These protected areas have just been established and are still subject to some types of degradation as a result of illicit exploitation. Continuing decline is also projected at one of the other locations due to wood harvesting, forest conversion and artisanal mining. Therefore, N. greeniana is assigned a preliminary status of “Endangered” [EN B1ab(iii)+2ab(iii)].

120 Boissiera 70

Notes

Noronhia greeniana most closely resembles N. divaricata , from which it differs by its semi-deciduous (vs. persistent), oblate (vs. elliptic to rhombic) and cuspidate (vs. rounded to acute) leaves, and by its punctate and rostellate (vs. smooth and apiculate) fruits.

Paratypi

MADAGASCAR. Prov. Antsiranana: Andavakoera, Andranonankomba, Montagne des Français , 12°21’00”S 49°21’34”E, 112 m, 8.IX.2004, Randrianaivo et al. 1085 ( CNARP, MO, TAN) ; Daraina, forêt d’Ampondrabe , 12°57’40”S 49°42’19”E, 340 m, 8.IV.2004, Ranirison 581 (Daraina, G, K, MO, TEF) ; Daraina, Befarafara, Solanampilana , 13°05’56”S 49°35’29”E, 110 m, 16.XI.2005, Ratovoson et al. 1102 ( CNARP, G, MO, P, TAN) .

Figures

Fig. 22. Photographs of Noronhia Stadtm. ex Thouars

Fig. 23. Noronhia greeniana Hong-Wa.

Fig.19. Distribution maps of species of Noronhia Stadtm.ex Thouars.N.edentata (H.Perrier) Hong-Wa to N.insularis (Labat,M.PignaL & O. PascaL) Hong-Wa & Besnard.