Noronhia maculata

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 : 168-169

50. Noronhia maculata Hong-Wa, spec. nova ( Fig. 33C , 35 ).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA, Diégo II, Ramena , env. 2 km à l’O d’Andavakoera , près de la grotte et du campement la Casa Aventura, 12°19’41’’S 49°20’26’’E, 76 m, 3.VIII.2007, Hong-Wa et al. 514 (holo-: MO- 6386603 !; iso-: CNARP!, G [ G00341577 ]!, P!, TAN!) .

Diagnosis

Noronhia maculata Hong-Wa can be distinguished from other members of the genus by its partially woody petioles, its maculate leaf blades, its short pedicels, and its subrotate, yellow-green flowers.

Description

Trees to 7 m tall, trunk to 10 cm diameter; young twigs cylindrical, 0.9-1.8 mm diameter, glabrous; bark medium gray, smooth. Leaves opposite, persistent; bud scales rarely persistent; blades medium green above, lighter below, obovate, 3.5-7 3 1.5-3 cm, subcoriaceous, glabrous, domatia casual, base attenuate, margin flat, apex retuse, midrib slightly sunken above, distinctly raised below, secondary veins conspicuous only below, 6-9 per side, 5-11 mm apart, looping 1-3 mm from the margin; petiole medium gray, 3-7 3 0.9-1.5 mm, partially to entirely woody, glabrous. Thyrses solitary to geminate, multiflorous, compact; peduncle 5-7 mm long, moderately pubescent; pedicel 2-3 mm long, moderately pubescent; calyx moderately to sparsely pubescent outside, glabrous inside, lobes deltate, 1-1.5 3 1-1.5 mm; corolla yellow-green, subrotate, 3-5 mm long, glabrous on both sides, the tube 1.4-1.5 mm long, lobes ovate, apex acute; corona present, 1.3-1.5 mm long, undivided; stamens 1.4-1.5 mm long, anthers obovate, 1.1-1.3 mm long; pistil 2.4-2.5 mm long, stigma capitate. Fruiting pedicel 2-10 3 0.8-1.7 mm; young fruits green, brownish to blackish when mature, ovoid, 11-17 3 7.5-11.5 mm, smooth, often covered with a pellicle, apex flat to rostellate, the rostellum flattened, slightly ridged, rounded, with the persistent style; dry pericarp 0.4-0.8 mm thick; endocarp woody.

Etymology

Noronhia maculata has distinctively spotted to mottled leaves, for which the Latin word is used to form the specific epithet.

Distribution, ecology and phenology

Noronhia maculata occurs in low-elevation dry forests from Montagne des Français to Ankarana in the north ( Fig. 36 ). It produces flowers and fruits from December to August.

Conservation status

There were 12 collections representing 12 localities available for analysis, which resulted in an EOO of 835 km 2, an AOO of 44 km 2, and six subpopulations representing five locations, of which three occur within protected areas (Ankarana, Mon-tagne d’Ambre, and Montagne des Français). Land conversion, charcoal production, and forest exploitation currently affect non-protected areas, whereas those benefiting from protection suffer from encroachment and illegal logging, all of which will lead to continuing decline in habitat quality and habitat loss as well as loss of mature individuals. Therefore, N. maculata is assigned a preliminary status of “Endangered” [EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)].

Notes

Noronhia maculata is similar to N. ankaranensis , but can be distinguished by its woody (vs. non-woody) petioles, short (less than 3 mm vs. 3-8 mm long) pedicels, and subrotate (vs. cupuliform) flowers. Its distinctive features include partially woody petioles, maculate leaf blades, short pedicels and subrotate, yellow-green flowers. The labels accompanying specimens of De Block 1200 mention flowers that are reddish-brown outside and whitish inside, but the specimen is otherwise morphologically similar to the other specimens cited here. It is not clear whether the distinctive color of De Block 1200 is related to the age of its flowers, as is sometimes the case in other species, or the result of hybridization. It might also indicate that this collection represents a different entity that is otherwise identical to N. maculata in all other macromorphological features. These specimens are best accommodated in N. maculata pending further studies of micromorphology, anatomy and/or genetics.

Paratypi

MADAGASCAR. Prov. Antsiranana: Ambilobe, Marivorahona , Andakoroa , Mahamasina , Ankarana RS, 12°56’34”S 49°07’01”E, 133 m, 7.XII.2006, Andriamihajarivo et al. 1044 ( MO, P, TAN); ibid. loc., Campement des Anglais , 12°54’59”S 49°06’24”E, 180 m, 6.VII.1994, Andrianantoanina & Rabeharinosy 718 ( G, K, MO, P, TAN); ibid. loc., from Campement des Anglais towards Campement des Américains (not beyond first savanna), 12°50’47”S 49°06’18”E, 82 m, 13.I.2002, De Block 1200 ( MO, B, BR, G, P, TAN, US) ; Marivorahona, Betsimiranja , 12°56’27”S 49°07’21”E, 136 m, 18.I.2009, Hong-Wa 570 ( MO, P, TAN); Sakaramy, Montagne d’Ambre PN, 12°26’40”S 49°13’56”E, 300 m, 29.V.2010, Hong-Wa 698 ( MO, TAN); Mahavanona, Andranomanitra , Ampitiliantsambo , 12°22’49”S 49°22’55”E, 418 m, 15.I.2005, Rakotonandrasana et al. 906 ( CNARP, MO, P, TAN); Montagne des Français , 12°23’13”S 49°22’50”E, 291 m, 17.VI.2004, Ramananjanahary et al. 24 ( CNARP, MO, P, TAN); ibid. loc., 12°21’06”S 49°21’49”E, 170 m, 7.X.2004, Randriambololomamonjy 28 ( MO, P, TAN); ibid. loc., 12°22’05”S 49°19’37”E, 382 m, 8.II.2005, Randrianarivelo et al. 215 ( G, MO, P, TAN); Marivorahona, Betsimiranjana , Ampondrabe , 5 km au SE de Mahamasina, Ankarana, 12°58’57”S 49°09’50”E, 127 m, 10.XII.2007, S. Randrianasolo et al. 633 ( CNARP, G, MO, P, TAN); Ramena, Andavakoera , forêt d’Andranonakomba , 12°21’03”S 49°21’29”E, 50 m, 5.XII.2007, Ratovoson et al. 1436 ( CNARP, G, MO, P, TAN) .

Figures

Fig.33.Photographs of Noronhia Stadtm.ex Thouars

Fig. 35. Noronhia maculata Hong-Wa.

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