Noronhia olearia

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 : 194-195

59. Noronhia olearia Hong-Wa, nom. nov. ( Fig. 43A).

≡ Olea ambrensis H. Perrier in Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 2: 277. 1949 [non Noronhia ambrensis H. Perrier in Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 2: 277. 1949].

Typus: M ADAGASCAR. Prov. Antsiranana: Centre (Nord): Montagne d’Ambre , près de Diégo-Suarez, [12°33’S 49°08’E], 1000-1200 m, IX.1926, Perrier de la Bâthie 17706 (holo-: P [ P00162996 ]!) .

Description

Trees to 10 m tall, trunk to 30 cm diameter; young twigs cylindrical, 0.5-2 mm diameter, glabrous; bark medium gray, smooth, sometimes lenticellate. Leaves opposite, persistent; bud scales persistent; blades dark green above, lighter below, lanceolate, 4-11 3 1.6-4.3 cm, coriaceous, glabrous, domatia absent, base acute to attenuate, margin flat to slightly undulate, apex acute to acuminate, the acumen 1-9 mm long, midrib slightly sunken above, raised below, secondary veins conspicuous, 7-12 per side, 4-19 mm apart, looping 1-5 mm from the margin; petiole yellow, 4-14 3 0.9-2 mm, usually not woody, sometimes only partially, glabrous. Flowers unseen, but infructescence thyrsoid. Fruiting pedicel 4-13 3 0.5-2 mm; young fruits green, reddish brown when mature, ovoid, 11-22.5 3 8-16 mm, surface smooth, sometimes verrucose, apex apiculate; dry pericarp 0.4-0.6 mm thick; endocarp woody; seed 11-16 3 6.5-12 mm.

Distribution, ecology and phenology

Noronhia olearia occurs in low- to mid-elevation transitional forests in the north, from Cap St. Sébastien to Montagne d’Ambre ( Fig. 36). It fruits from January to June.

Conservation status

The assessment included 10 collections representing eight localities and resulted in an EOO of 377 km 2, an AOO of 28 km 2, and four subpopulations representing three locations, of which two occur within a protected area (Montagne d’Ambre). One of the subpopulations occurs in an area that is now highly degraded as a result of land conversion for agriculture and pasture, and other forms of forest exploitation. The subpopulations within Montagne d’Ambre PN, especially those at the periphery, also suffer from illicit exploitation of wood and other forest products as well as encroachment for crop and khat cultivation. All these threats will lead to decline in habitat quality and number of individuals as well as habitat loss. Therefore, Noronhia olearia is assigned a preliminary status of “Endangered” [EN B1ab(i,i i,iii,iv,v)+2ab(i,ii,iii,iv,v)].

Notes

Noronhia olearia can be recognized by its yellow to reddish petioles and apiculate to rostrate fruits, which are often covered with a white pellicle. It differs from N. linocerioides by its lanceolate (vs. elliptic), coriaceous (vs. chartaceous) leaf blades, and smooth to verrucose (vs. smooth to punctate) fruits with an apiculate to rostrate (vs. rostellate) apex. This species was first described as Olea ambrensis , whose type (Perrier de la Bâthie 17706) morphologically resembles the following specimens: Andrianantoanina 130, 313 and 366, Hong-Wa 573 and 693, Leeuwenberg 14309 and Schatz 1501. Another collection, Richard 192 [ P 00701261, P 04046974], identified by PERRIER DE LA BâTHIE as Noronhia ambrensis , also belongs to this group. Molecular studies placed material of Hong-Wa 573 and 693 deep within Noronhia (HONG- WA & BESNARD, 2013, 2014) rather than within Olea . Similarly, other specimens recognized as O. ambrensis by GREEN (2002) fell elsewhere within Noronhia , close to collections to which they resemble (e.g. Schatz 3605 in N. linocerioides ). Since the binomial Noronhia ambrensis is already occupied and no other validly published names are available for the entity described as Olea ambrensis , a new name is proposed here.

Additional specimens examined

MADAGASCAR. Prov. Antsiranana: Joffreville, Montagne d’Ambre PN, 12°31’S 49°09’E, 700-900 m , 3-11. V .1993 , Andrianantoanina et al. 130 ( G, MO, P, TAN); ibid. loc., 12°27’S 49°13’E, 250-500 m, 3-10.VIII.1993, Andrianantoanina & Rochsceohclher 269 ( K, MO, P); ibid. loc., 12°35’S 49°09’E, 1475 m, 26. VIII-IX . 1993, Andrianantoanina 313 ( K, MO, P, TAN); ibid. loc., 12°27’S 49°13’E, 250-500 m , 29.IX-5.X.1993, Andrianantoanina 366 ( K, MO); ibid. loc., 12°33’S 49°08’E, 1000 m , 22. I .2009 , Hong-Wa 573 ( G, MO, P, TAN); ibid. loc., 12°31’43”S 49°10’21”E, 993 m, 18. V .2010 , Hong-Wa & Ortiz 693 ( G, MO, P, TAN); ibid. loc., near Station des Roussettes , 12°31’S 49°10’E, 1000 m, 23. I .1994 , Leeuwenberg 14309 ( MO, P, WAG); Cap St. Sébastien, [12°26’S 48°44’E], 1837, Richard 192 ( P); Ambohitra ( Joffreville ), Montagne d’Ambre PN, 12°33’S 49°08’E, 1000 m, 13.IX.1987, Schatz 1501 ( MO, P, TAN); ibid. loc., [12°33’S 49°08’E] , 19. V .1987 , Service Forestier 31599 ( TEF).