Noronhia orientalis

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 : 197-198

60. Noronhia orientalis Hong-Wa, spec. nova ( Fig. 43B , 44 ).

Typus: MADAGASCAR. Prov. Antsiranana: SAVA , Sambava , Anjangoveratra , Ambavala , forêt d’Antsahakasaka , 2 km au NO du village Ambavala, 14°05’39”S 50°02’42”E, 146 m, 16.II.2006, Andrianjafy et al. 1599 (holo-: MO- 6615571 !; iso-: G [ G00341629 ]!, P!, TAN!) .

Diagnosis

Noronhia orientalis Hong-Wa can be distinguished from other members of the genus by its terminally verticillate leaves, its obovate leaf blades, with very conspicuous venation and its compact inflorescences with white flowers.

Description

Trees to 10 m tall, trunk to 10 cm diameter; young twigs cylindrical, 1.5-3.1 mm diameter, glabrous; bark dark gray, smooth to rugose, sometimes lenticellate. Leaves opposite, sometimes verticillate at the tips of the branches, persistent; bud scales persistent; blades medium green above, lighter below, oblong to obovate, 7-15 3 2.5-5 cm, subcoriaceous, glabrous, domatia casual to abundant, base acute to attenuate, sometimes truncate, margin flat, slightly revolute, apex retuse to shortly cuspidate, the cusp 1-6 mm long, midrib sunken above, distinctly raised below, secondary veins conspicuous, 10-15 per side, 8-16 mm apart, looping 2-5 mm from the margin; petiole light gray to brownish, 6-22 3 1.5-3 mm, entirely woody, glabrous. Thyrses geminate to fasciculate, pauciflorous, compact; peduncle 5-10 mm long, glabrous; pedicel 3-4 mm long, glabrous; calyx glabrous on both sides, lobes triangular, 0.7-1.2 3 1-1.2 mm; corolla white, cupuliform, 3-4.5 mm long, glabrous on both sides, the tube 1.5-3 mm long, lobes ovate, apex acute; corona present, 1.6-2 mm long, undivided; stamens 1.5-2 mm long, anthers oblong, 0.7-1.3 mm long; pistil 2-2.3 mm long, slightly bilobed. Fruiting pedicel 8-10 3 3-3.5 mm; young fruits green, unseen mature, ovoid to oblong, 18-21 3 14-15 mm, surface smooth, sometimes glaucous and slightly rugose, apex flat; dry pericarp 1mm thick; endocarp woody; seed 10-15 3 6-10 mm.

Etymology

The specific epithet refers to its strictly eastern distribution, specifically northeastern Madagascar.

Distribution, ecology and phenology

Noronhia orientalis occurs in littoral to low-elevation humid forests in the northeast, from Antsirabe Nord to the Masoala peninsula ( Fig. 36 ). It has been collected in flowers and fruits in February.

Conservation status

Noronhia orientalis is currently known from seven collections representing seven localities. With an EOO of 4,012 km 2, an AOO of 28 km 2, and five subpopulations representing five locations, of which four occur within protected areas (Makirovana-Tsi-homanaomby, Marojejy, and Masoala), N. orientalis is assigned a preliminary status of “Endangered” [EN B1ab(ii,iii,v)+2ab(ii,iii,v)] because habitat loss as well as continuing decline in habitat quality and number of mature individuals is projected both outside and inside of protected areas due to wood harvesting, land conversion and illicit exploitation.

198 Boissiera 70

Notes

Noronhia orientalis and N. retusifolia Hong-Wa are similar in appearance but can be distinguished from each other by the shape of their leaves (oblong to obovate in N. orientalis vs. oblanceolate to obovate in N. retusifolia ), the length of their petioles (up to 22 mm vs. less than 11 mm), and the surface (smooth to sometimes slightly rugose vs. rugose) and apex (flat vs. bluntly pointed) of their fruits. Features such as terminally verticillate leaves, obovate leaf blades, with very conspicuous venation and compact inflorescences with white flowers characterize this species.

Paratypi

MADAGASCAR. Prov. Antsiranana: Sambava, Anjangoveratra , forêt d’Andalibe , 14°07’35”S 50°03’07”E, 115 m, 23.III.2009, Hong-Wa 636 ( MO, P, TAN) ; Vohémar, Antsirabe Nord, Andravinambo , forêt d’Antsaolatra , 14°06’24”S 49°58’39”E, 328 m, 31. I.2014, Martial et al. 432 ( DOV, MO, P, TAN) ; Sambava, Anjagoveratra, Ambavala , forêt de Tsihomanaomby , 14°06’36”S 50°02’41”E, 330 m, 15. II.2014, Martial et al. 498 ( MO, P, TAN) ; Masoala PN, Beankoraka , 15°57’S 50°13’E, 14.XI.1994, Rahajasoa et al. 888 ( MO, TAN) ; Sambava, Andratamarina , 14°25’48”S 49°50’45”E, 451 m, 19.X.2010, Ravelonarivo & Raharivelo 3516 ( MO, P, TAN) . Prov. Toamasina: Masoala PN, Antalavia , 15°47’S 50°02’E, 0 m, 27.XI.1994, Rahajasoa et al. 1078 ( MO) .

Figures

Fig.43.Photographs of Noronhia Stadtm.ex Thouars

Fig. 44. Noronhia orientalis Hong-Wa.

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