Noronhia marojejyensis, Hong-Wa, 2016

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 : 177

53. Noronhia marojejyensis Hong-Wa, spec. nova ( Fig. 38).

Typus: MADAGASCAR. Prov. Antsiranana: SAVA , Marojejy RNI; along the southern edge of the reserve at the base of Mt. Beondroka , 14°27’S 49°47’E, 230 m, 28.XI.1989, Miller & Randrianasolo 4642 (holo-: MO-3759776!; iso-: MO-3759775!, P [ P03532774 , P03532775 ]!, TAN!) .

Diagnosis

Noronhia marojejyensis Hong-Wa can be distinguished from other members of the genus by its oblong leaf blades, turning glossy reddish-brown on drying, its compact, pale yellow inflorescences, and its punctate fruits, with woody endocarp.

Description

Trees to 5 m tall; young twigs cylindrical, 1.2-1.9 mm diameter, glabrous; bark light brown, smooth to somewhat rugose, flaky. Leaves opposite, persistent; bud scales deciduous; blades dark green above and below, oblong, 9.4-16.1 3 2.6-4.5 cm, coriaceous, glabrous, domatia absent, base acute to attenuate, margin flat, apex acuminate, the acumen 8-17 mm long, midrib slightly sunken above, distinctly raised above, secondary veins conspicuous, 13-16 per side, 6-19 mm apart, looping 2-5 mm from the margin; petiole light brown, 8-9 3 2-2.5 mm, entirely woody, glabrous. Thyrses geminate to fasciculate, multiflorous, compact; peduncle 5 mm long, moderately pubescent; pedicel 5-8 mm long, moderately pubescent; calyx moderately pubescent outside, glabrous inside, lobes triangular, 0.8-1.3 3 1-1.3 mm; corolla pale yellow, urceolate, 4.5-5 mm long, glabrous on both sides, the tube 2.5-3 mm long, lobes widely ovate, apex rounded; corona present, 1.7-1.8 mm long, lobed; stamens 1.7-2 mm long, anthers widely obovate, 1.4 mm long; pistil 2 mm long, stigma capitate to slightly bilobed. Fruiting pedicel 4-7 3 1.5-2 mm; young fruits green, dark purple-brown when mature, subglobose, 19.5-21 3 18-20 mm, surface covered with white dots, apex flat; dry pericarp 0.8 mm thick; endocarp woody; seed 11 3 9 mm.

Etymology

The specific epithet is derived from the name of the massif in northeastern Madagascar, the only place where the species is known to occur.

Distribution, ecology and phenology

Noronhia marojejyensis occurs in low-elevation humid forests on quartzites on Marojejy in northeastern Madagascar ( Fig. 36 ). It has been collected in flowers and fruits in November.

Conservation status

This species is known only from a single collection from low-elevation within Marojejy PN. With an AOO of just 4 km 2, coupled with habitat degradation in this part of the protected area resulting from illicit exploitation of timber and non-timber forest products, N. marojejyensis is assigned a preliminary status of “Critically Endangered” [CR B2ab(iii,v)].

Notes

Noronhia marojejyensis resembles N. pervilleana (Knobl.) H. Perrier , from which it differs by its entirely (vs. partially) woody petioles, oblong (vs. lanceolate) leaf blades, urceolate (vs. rotate), pale yellow (vs. white sometimes tinged purplish) corolla, and subglobose (vs. ovoid) fruits with a flat (vs. rostellate) apex.

Figures

Fig. 36. Distribution maps of species of Noronhia Stadtm. ex Thouars.N. maculata Hong-Wa to N. perrieriana Hong-Wa.