Noronhia variabilis 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 : 272-274

85. Noronhia variabilis Hong-Wa , spec. nova ( Fig. 69 , 70).

– Noronhia sp. 2 , sp. 4 in GAUTIER (2002: 202).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA , Ambato FC, à 40 km au N d’Ambanja sur le versant S de la Montagne d’Ambato, 13°26’S 48°33’E, 90-459 m, 22.XI.1996, Randrianaivo et al. 27 (holo-: MO-6615560!; iso-: G, NY, P [ P03559017 ]!, TAN!) .

Diagnosis

Noronhia variabilis Hong-Wa can be distinguished from other members of the genus by its often non-woody, reddish petioles, its coriaceous, elliptic to oblong leaf blades, and its ovoid to subglobose fruits, with smooth surface and woody endocarp.

Description

Trees to 15 m tall, trunk to 12 cm diameter; young twigs cylindrical to flattened, 1-2.7 mm diameter, glabrous; bark dark gray, smooth. Leaves opposite, persistent; bud scales persistent to deciduous; blades light green above, yellowish below, elliptic to oblong, 4.5-13 3 2-5 cm, coriaceous, glabrous, domatia absent, base attenuate, margin flat, apex acute, the point 1-5 mm long, midrib slightly sunken above, distinctly raised below, secondary veins slightly conspicuous, 5-12 per side, 6-19 mm apart, looping 2-5 mm from the margin; petiole reddish, 4-15 3 1-2.5 mm, usually not woody, glabrous. Flowers unseen, but infructescence thyrsoid. Fruiting pedicel 2-11 3 1.5-6.5 mm; young fruits green, purple black when mature, ovoid to subglobose, 12-26 3 10.5-22 mm, smooth, apex flat to apiculate; dry pericarp 0.6-1.6 mm thick; endocarp woody; seed 13.5-21 3 10-15 mm.

Etymology

The specific epithet refers to the variability found within this taxon, especially in the shape and size of its leaves.

Distribution, ecology and phenology

Noronhia variabilis occurs in low- to high-elevation humid forests in the northern region, from Daraina to Manongarivo ( Fig. 68 ). It fruits from May to August.

Conservation status

The assessment included 13 collections representing 12 localities and resulted in an EOO of 5,196 km 2, an AOO of 36 km 2, and eight subpopulations representing seven populations, of which five occur within protected area (Galoko, Loky-Manambato, and Manongarivo). Wood harvesting, illicit exploitation, and land conversion are projected to lead to continuing decline in habitat quality, AOO and number of mature individuals in the near future. Therefore, N. variabilis is assigned a preliminary status of “Vulnerable” [VU B1ab(ii,iii,v)+2ab(ii,iii,v)].

274 Boissiera 70

Notes

Noronhia variabilis resembles N. macrocarpa , from which it differs by its elliptic to oblong (vs. lanceolate to obovate) leaves with an acute (vs. acuminate) apex, and its ovoid to subglobose (vs. ovoid) and smooth (vs. rugose) fruits with a flat to apiculate (vs. flat to bluntly pointed) apex. The new species can be recognized by its often non-woody, reddish petioles, coriaceous, elliptic to oblong leaf blades, and ovoid to subglobose fruits.

Paratypi

MADAGASCAR. Prov. Antsiranana: Antsatrotro, Manongarivo RS, 14°04’57”S 48°22’49”E, 1350 m, 17.VIII.1994, Andriatsiferana et al. 1695 ( G, MO, TAN) ; ibid. loc., 14°04’57”S 48°22’49”E, 1350 m, 17.VIII.1994, Andriatsiferana et al. 1704 ( MO) ; Ambilobe, Beramanja, Anketrabe , forêt de Kalabenono , 13°38’31”S 48°40’25”E, 700 m, 25.XI.2006, Callmander et al. 607 ( G, MO, P, TAN) ; Ambahatra , cours supérieur, 13°59’S 48°26’E, 850 m, 28. II.1999, Gautier 3432 ( G, MO) ; Daraina, forêt d’Antsahabe , 13°13’23”S 49°32’47”E, 1030 m, 24.XI.2004, Gautier 4740 (Daraina, G, K, MO, TEF) ; Manongarivo Massif , E of Ankaramy, 14°05’S 48°20’E, 1100-1175 m, 19.X.1994, McPherson & van der Werff 16419 ( G, K, MO, TAN) ; Manongarivo RS, Ankaramibe, Antsatrotro , 14°04’57”S 48°22’53”E, 1350 m, 13.VIII.1994, Rahajasoa et al. 384 ( K, MO, P) ; ibid. loc., 14°05’S 48°24’E, 679-1876 m, 12. I.1994, Rakotomalala 120 ( G, MO, P) ; Vohémar, Daraina, forêt d’Ampondrabe , 12°57’29”S 49°41’50”E, 580 m, 11.IV.2004, Ranirison 634 (Daraina, G, K, MO, TEF) ; Ambilobe, Beramanja, Anketrabe , forêt de Kalabenono , 13°38’40”S 48°40’26”E, 700 m, 28.IX.2013, Ratovoson 2042 ( G, MO, P, TAN) ; ibid. loc., 13°39’01”S 48°40’26”E, 800 m, 27.XI.2006, Razafitsalama 1180 ( MO, TAN) ; Ambanja, Marovato , [13°58’S 48°50’E], 15.VII.1953, Réserves Naturelles 5740 ( P, TEF) .

Figures

Fig. 69. Noronhia variabilis Hong-Wa.

Fig. 68. Distribution maps of species of Noronhia Stadtm. ex Thouars.N. urceolata H. Perrier to Noronhia verticillata H. Perrier.