Noronhia clarinerva

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 : 69-71

13. Noronhia clarinerva Hong-Wa, spec. nova ( Fig. 7B , 10).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA , Diégo II , Sakaramy, Montagne d’Ambre AP, 12°26’25”S 49°13’49”E, 319 m, 2. VI .2010, Hong-Wa 708 (holo-: MO-6400693!; iso-: P!, TAN!).

Diagnosis

Noronhia clarinerva Hong-Wa can be distinguished from its congeners by its oblong to rhombic, coriaceous leaf blades, its light-colored venation and its fasciculate pinkish flowers.

Description

Shrubs to 5 m tall, trunk to 3 cm diameter; young twigs cylindrical, 0.8-1.4 mm diameter, glabrous; bark whitish, smooth. Leaves opposite, persistent; bud scales persistent only on very young twigs; blades medium green above, lighter below, oblong to rhombic, 4.5-7.5 3 1-2.5 cm, coriaceous, glabrous, domatia absent, base acute, margin flat to slightly undulate, apex acuminate, the acumen 2-16 mm long, midrib sunken above, raised below, secondary veins conspicuous mostly below, 7-12 per side, 5-10 mm apart, looping 1-2 mm from the margin; petiole light gray to whitish, 3.5-7 3 1-2.5 mm, entirely woody, glabrous. Flowers fasciculate; pedicel 3-4 mm long, glabrous; calyx moderately pubescent outside, glabrous inside, lobes deltate, 2 3 1.5 mm; corolla pinkish, urceolate, 4.5 mm long, glabrous on both sides, the tube 3.5 mm long, lobes widely ovate, apex obtuse to acute; corona present, 1.7 mm long, undivided; stamens 2 mm long, anthers oblong, 1.8 mm long; pistil 2.5 mm long, stigma slightly bilobed. Fruiting pedicel 5-11 3 0.8-1.6 mm; young fruits green, brown when mature, ovoid, 10-13.5 3 6.5-9 mm, surface smooth, apex apiculate; dry pericarp 0.4-0.7 mm thick; endocarp woody.

Etymology

Noronhia clarinerva has distinctively light-colored veins, which are almost white on dry specimens, thus the name of the species.

Distribution, ecology and phenology

Noronhia clarinerva occurs in low- to mid-elevation dry forests in the north, from Montagne d’Ambre to Daraina ( Fig. 9 ). It produces flowers and fruits from December to June.

Conservation status

Noronhia clarinerva is currently known from nine collections representing eight localities, which are encompassed within an EOO of 1,066 km 2, an AOO of 28 km 2, and four subpopulations representing four locations. All but one location occur entirely within protected areas (Loky-Manambato and Montagne d’Ambre) whereas the fourth sits just at the border of Montagne d’Ambre PN, with some individuals actually found outside of it. With the gradual encroachment for crop cultivation, wood harvesting, illegal logging, and cattle grazing already taking place there, this location is susceptible to decline in habitat quality and loss of mature individuals in the near future. Therefore, N. clarinerva is assigned a preliminary status of “Endangered” [EN B1ab(iii,v)+2ab(iii,v)].

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Notes

Noronhia clarinerva closely resembles N. crassinodis , but differs by lacking bud scales at maturity and by having lighter-colored and more conspicuous venation, oblong to rhombic (vs. obovate), acuminate (vs. mucronulate) leaf blades, and pinkish (vs. red purplish) flowers.

Paratypi

MADAGASCAR. Prov. Antsiranana: Daraina, Ankijabe , forêt de Bekaraoka , 13°10’02”S 49°42’38”E, 150 m, 15.III.2003, Gautier et al. 4386 ( Daraina , G, K, MO, P, TEF); Montagne d’Ambre PN , 12°29’22”S 49°10’16”E, 670 m, 8.XII.2006, Gautier & Chatelain 5084 ( G, K, MO, P, TAN, TEF); ibid. loc ., 12°25’40”S 49°13’56”E, 300 m, 29. V .2010, Hong-Wa 694 ( MO, P, TAN); ibid. loc ., 12°26’40”S 49°13’56”E, 300 m, 29. V .2010, Hong-Wa 696 ( MO, TAN); ibid. loc ., 12°26’28”S 49°13’58”E, 331 m, 1. VI .2010, Hong-Wa 704 ( MO, P, TAN); Analamazava, part of Binara Range, SW of Daraina , 13°15’S 49°38’E, 200-1180 m, 20.IV.1990, Meyers 98 ( G, MO, P, TAN); Daraina , forêt de Binara , 13°15’21”S 49°37’00”E, 340 m, 18.XII.2003, Nusbaumer 821 ( Daraina , G, K, MO, TAN); Montagne d’Ambre , 12°29’16”S 49°10’21”E, 650 m, 4. VI .2008, Trigui et al. 535 ( G, MO, TEF) .

Figures

Fig. 7. Photographs of Noronhia Stadtm.ex Thouars. A. Noronhia christenseniana Hong-Wa [Ratovoson 1280]; B. Noronhia clarinerva Hong-Wa [Nusbaumer 821]; C. Noronhia cochleata Labat, M. PignaL & O. PascaL [Labat 3258]; D. Noronhia comorensis S. Moore [Barthelat 537]; E. Noronhia cordifolia (Labat, M. PignaL & O. PascaL) Hong-Wa & Besnard [Barthelat 788].

Fig. 9. Distribution maps of species of Noronhia Stadtm.ex Thouars. N. christenseniana Dubard to N. domatifera Bosser.