Noronhia latifolia

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 : 143-144

41. Noronhia latifolia Hong-Wa, spec. nova ( Fig. 29 , 30A ).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA, Ambilobe , Beramanja , Anketrabe , forêt de Kalabenono, chaîne de Galoko, 9 km au SE d’Anketrabe, 13°38’30”S 48°40’53”E, 976 m, 23.XI.2006, Razafitsalama 1102 (holo-: MO- 6615570 !; iso-: G [ G00341579 ], P [ P03533079 ] image seen, TAN!) .

Diagnosis

Noronhia latifolia Hong-Wa can be distinguished from other members of the genus by its whitish bark, its enlarged nodes, its thick woody petioles, its broad leaf blades, and its subglobose, punctate fruits.

Description

Shrubs to 7 m tall, trunk to 6 cm diameter; young twigs cylindrical, 2.3-3.5 mm diameter, glabrous; bark whitish, smooth. Leaves opposite, persistent; bud scales deciduous; blades medium green above, lighter below, broadly lanceolate, 14-28.5 3 3.5-9.5 cm, coriaceous, glabrous, domatia absent, base acute, margin flat, apex acute, the point 10-14 mm long, midrib slightly sunken above, distinctly raised below, secondary veins conspicuous, 9-14 per side, 26-29 mm apart, looping 3.5-7 mm from the margin; petiole light gray, 13-20 3 3.6-4.7 mm, entirely woody, glabrous. Flowers unseen, but infructescence thyrsoid. Fruiting pedicel 8-12 3 1.7-2.2 mm; young fruits green, brownish when mature, subglobose, 14.5-20.5 3 13-17 mm, covered with white dots, apex flat to apiculate; dry pericarp 0.7-1.1 mm thick; endocarp crustaceous; seed 10.5-14 3 9-11 mm.

Etymology

This species derives its name from its broad leaves.

Distribution, ecology and phenology

Noronhia latifolia occurs in mid-elevation humid forests in the Galoko mountain chain in northern Madagascar ( Fig. 27 ). This species has been collected in fruits in November.

Conservation status

Noronhia latifolia is currently known only from three collections made within the same forest (Kalobinono on the Galoko range) gathered within a distance of no more than 80 m from each other, and two were probably from adjacent individuals. With a distribution that is almost linear, EOO could not be calculated, AOO was estimated at 4 km 2, and the single subpopulation represents a single location that is now encompassed within the newly established protected area of Galoko. Although extensive clearing of the Kalobinono forest may now be slowing as a result of its new status, there is a reason to believe that anthropogenic pressure, such as illicit exploitation or encroachment, will not be entirely eliminated, especially in the context of a changing climate that modulates farming practices and exploitation of natural resources, rapid population growth, and sustained immigration influx. Therefore, N. latifolia is assigned a preliminary status of “Vulnerable” [ VU D2 ] .

144 Boissiera 70

Notes

Noronhia latifolia resembles N. edentata , but can be distinguished by its broadly lanceolate (vs. elliptic to obovate) and longer (14-28.5 cm vs. 5-17 cm) leaf blades, acute (vs. rounded to acuminate) leaf apex, and crustaceous (vs. woody) endocarp.

Paratypus

MADAGASCAR. Prov. Antsiranana: Ambilobe, Beramanja , Anketrabe , forêt de Kalabenono , 13°38’41”S 48°40’27”E, 730 m, 26.XI.2006, Callmander et al. 626 ( G, MO, P, TAN); ibid. loc., 13°38’40”S 48°40’26”E, 700 m, 28.IX.2013, Ratovoson 2041 ( MO, P, TAN) .

Figures

Fig. 29. Noronhia latifolia Hong-Wa.

Fig.30.Photographs of Noronhia Stadtm.ex Thouars

Fig. 27. Distribution maps of species of Noronhia Stadtm. ex Thouars. N. intermedia Hong-Wa to N. macrocarpa Hong-Wa.