Noronhia ratovosonii

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 : 223-224

69. Noronhia ratovosonii Hong-Wa, spec. nova ( Fig. 54).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA , Andranovondronina , Anjiabe , forêt de Belamoty, à 3 km au NE, 12°06’09”S 49°19’34”E, 85 m, 10.XI.2006, Ratovoson et al. 1153 (holo-: MO- 6615566 !; iso-: CNARP, G, P [ P04254202 ] image seen, TAN) .

Diagnosis

Noronhia ratovosonii Hong-Wa can be distinguished from other members of the genus by its coriaceous, linear to obovate leaf blades, with a retuse to obcordate apex, and its ovoid, somewhat rugose fruits.

Description

Shrubs to 2 m tall, trunk to 5 cm diameter; young twigs cylindrical, 1-1.5 mm diameter, glabrous; bark medium gray, smooth to slightly rugose. Leaves opposite, persistent; bud scales persistent; blades medium green above, lighter below, linear to obovate, 4-6 3 1-2.5 cm, coriaceous, glabrous, domatia absent, base rounded, margin revolute, apex retuse to obcordate, sometimes slightly acuminate, the acumen 0-3 mm long, midrib sunken above, raised below, secondary veins inconspicuous, 6-8 per side, 5-12 mm apart, looping 1-2 mm from the margin; petiole light gray to whitish, 2.5-5 3 1-1.3 mm, entirely woody, glabrous. Flowers unseen, but fruits solitary. Fruiting pedicel 4-8 3 1-1.5 mm; young fruits green, brownish when mature, ovoid, 8.5-17.5 3 7-10 mm, surface smooth to rugose, sometimes covered with a white pellicle, apex rostellate, the rostellum flattened, ridged, rounded, with the persistent style; dry pericarp 0.7 mm thick; endocarp woody.

Etymology

This species is dedicated to Fidisoa “Fidy” Ratovoson, a botanist at the Missouri Botanical Garden in Madagascar, for collecting the type specimen and other numerous materials of Noronhia , for helping to locate specimens deposited at CNARP, TAN and TEF, and otherwise for assisting with various aspects of this work.

Distribution, ecology and phenology

Noronhia ratovosonii occurs in low-elevation dry forests on limestones and unconsolidated sands in the north, around Montagne des Français ( Fig. 49 ). Its flowering period is unknown, and it fruits from August to November.

Conservation status

Based on four collections representing three localities, the assessment yielded an EOO of 74 km 2, an AOO of 12 km 2, and three subpopulations representing three locations, of which only one occurs within a protected area (Montagne des Français). Suitable habitat, both outside and inside of protected areas, will likely continue to experience some form of degradation and loss resulting from [illicit] forest exploitation, invasive species, and expansion of agricultural fields. Consequently, N. ratovosonii is assigned a preliminary status of “Endangered” [EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)].

224 Boissiera 70

Notes

Noronhia ratovosonii is similar to N. longipedicellata , but can distinguished by its habit (shrubs vs. trees), retuse to obcordate (vs. retuse to mucronate) leaf blades, and shorter pedicels (less than 1 cm vs. 1-3 cm long). The new species can be recognized by its coriaceous, linear to obovate leaves and ovoid, somewhat rugose fruits.

Paratypi

MADAGASCAR. Prov. Antsiranana: Andranovondronina, Anjiabe, Antsaravy , forêt Antafian’i Tsirambaza , 12°08’53”S 49°20’31”E, 8 m, 17.III.2006, Guittou 318 ( CNARP, MO, P, TAN) ; Ramena, Andavakoera , 12°19’57”S 49°21’19”E, 172 m, 4.VIII.2007, Hong-Wa et al. 525 ( CNARP, MO, P, TAN) ; ibid. loc., Hong-Wa et al. 548 ( TAN) .

Figures

Fig. 49. Distribution maps of species of Noronhia Stadtm.ex Thouars. N. pervilleana (KnobL.) H. Perrier to N. seyrigii H. Perrier.