Noronhia similis, 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 : 247-248

77. Noronhia similis Hong-Wa, spec. nova ( Fig. 61 ).

Typus: MADAGASCAR. Prov. Antsiranana: DIANA , Massif du Tsaratanana, [13°49’S 48°44’E], 2100 m, XI.1966, Morat 2264 (holo-: MO-6149642!; iso-: P [ P00701309 , P03559031 ]!, TAN!) .

Diagnosis

Noronhia similis Hong-Wa can be distinguished from other members of the genus by its obovate leaf blades that are somehow tinged golden, sericeous to glabrescent at maturity, and its compact inflorescences with greenish white flowers.

Description

Trees to 10 m tall; young twigs flattened, 1.5-4.5 mm diameter, glabrous; bark light gray, rugose. Leaves opposite, persistent; bud scales deciduous; blades dark green above, lighter below, obovate, 5-11.5 3 3-5.5 cm, subcoriaceous, glabrous to sericeous, domatia casual, base rounded, margin flat, apex rounded to slightly acute, the point 1-3 mm long, midrib slightly sunken above, distinctly raised below, secondary veins conspicuous, 7-10 per side, 8-20 mm apart, looping 2-9 mm from the margin; petiole brownish, 5-13 3 1-2.5 mm, usually entirely woody, glabrous. Thyrses solitary to geminate, multiflorous, compact; peduncle 5-10 mm long, moderately to sparsely pubescent; pedicel 2-10 mm long, moderately to sparsely pubescent; calyx moderately to sparsely pubescent outside, glabrous inside, lobes triangular, 1-2 3 1-2.5 mm; corolla greenish white, subrotate, 3.5-5 mm long, glabrous on both sides, the tube 0-2.5 mm long, lobes oblong, apex obtuse; corona absent; stamens 2-4 mm long, anthers oblong to ovate, 1.7-2.8 mm long; pistil 2-3 mm long, stigma capitate. Fruiting pedicel 1-2 3 1-1.5 mm; young fruits green, unseen mature, ovoid, 10-11 3 7-8 mm, smooth to rugose, apex bluntly pointed, dry pericarp 0.5 mm thick; endocarp woody.

Etymology

The resemblance between Noronhia similis and N. broomeana was used as the basis for the specific epithet of the new species described here.

Distribution, ecology and phenology

Noronhia similis occurs in mid- to high-elevations humid forests on basement rocks and quartzites from the Tsaratanana massif to Makira in the north and from Ivohibe RS to Andohahela in the south ( Fig. 62 ). It has been collected in flowers from October to December.

Conservation status

Based on six collections representing six localities, the assessment indicated an EOO of 68,364 km 2, an AOO of 24 km 2, and six subpopulations representing six locations, all of which occur within protected areas (Analamazaotra, Andohahela, Corridor Ambositra-Vondrozo, Makira, Tsaratanana, and Tsaratanana-Ambohipiraka-Corridor Marojejy). Given the large distribution, number of locations and AOO, whose actual value is likely to exceed the estimated value, N. similis is assigned a preliminary status of “Least Concern”.

248 Boissiera 70

Notes

Noronhia similis most closely resembles N. broomeana , but differs from it mainly by its woody (vs. non-woody) petiole, oblong (vs. obovate) leaf blades, and connate (vs. almost free) petals. Obovate leaf blades that are somehow tinged golden, sericeous to glabrescent at maturity, and compact inflorescences with greenish white flowers characterize this new species.

Paratypi

MADAGASCAR. Prov. Antsiranana: Massif du Tsaratanana , vallon d’Ambatoafy, [13°49’S 48°44’E], XI.1966, Morat 2431 ( P, TAN) ; ibid. loc., haut bassin de la Maevarano , [13°58’12’’S 48°50’24’’E], 1750-2000 m, 6.XI.1966, Service Forestier 24980 ( P, TEF) . Prov. Fianarantsoa: Ivohibe RS, 22°28’12”S 46°57’36”E, 900 m, 9.X.1997, Rakotomalaza et al. 1393 ( G, MO, P, TAN) . Prov. Mahajanga: Befandriana-Nord , Matsoandakana , Ambotaharanana Andranomena, 15°07’48”S 49°20’38”E, 1146 m, 15.II.2008, Bernard 836 ( MO, P, TAN) . Prov. Toamasina: Analamazaotra RS, [18°56’S 48°26’E], 15.X.1953, Service Forestier 8566 ( P, TEF) ; ibid. loc., [18°56’S 48°26’E], 10.XI.1954, Service Forestier 12162 ( P, TEF) . Prov. Toliara: Andohahela PN, 24°33’S 46°52’E, 700- 850 m, 2.XII.1989, McPherson 14577 ( K, MO, P, TAN) .

Figures

Fig. 61. Noronhia similis Hong-Wa.

Fig. 62. Distribution maps of species of Noronhia Stadtm. ex Thouars.N. similis Hong-Wa to N. tubulosa H. Perrier.