Noronhia densiflora Bosser

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 : 93-94

23. Noronhia densiflora Bosser in Adansonia ser. 2, 13: 461. 1973 ( Fig. 15 ).

Typus: MADAGASCAR. Prov. Fianarantsoa: Route Farafangana-Vangaindrano , E de Madagascar, [22°49’S 47°49’E], XII.1963, Bosser 18739 (holo-: P [ P00413225 ]!; iso-: MO-4407063!, P [ P00413226 , P00413227 ]!, TAN!) .

Description

Shrubs to trees to 8 m tall, trunk to 12 cm diameter; young twigs cylindrical to subquadrangular, 3.5-6.5 mm diameter, glabrous; bark light brown to whitish, flaky. Leaves opposite, persistent; bud scales persistent; blades dark green above, lighter below, oblong, 22.5-62 3 7-17 cm, extremely coriaceous, glabrous, domatia absent, base rounded to cordate, margin revolute, apex acute to mucronate, sometimes rounded, the mucro (0-) 3-18 mm long, midrib sunken above, distinctly raised below, secondary veins very conspicuous, 11-18 per side, 25-64 mm apart, looping 7-17 mm from the margin; petiole light brown to white, 8-27 3 4-8 mm, entirely woody, with flaky bark, glabrous. Thyrses fasciculate, pauciflorous, compact; peduncle 7-12 mm long, sparsely pubescent; pedicel 7-15 mm long, sparsely pubescent; calyx sparsely pubescent outside, glabrous inside, lobes widely ovate, 1-1.5 3 1.2-1.7 mm; corolla purple-red, globose, 4-5 mm long, glabrous on both sides, the tube 3.8-4.5 mm long, lobes acute to obtuse, sometimes dentate; corona absent; stamens 2-2.5 mm long, anthers oblong, 1.5 mm long; pistil 3-3.5 mm long, stigma bilobed. Fruiting pedicel 1.5-1.8 3 1.8-2.5 mm; young fruits green, blackish when mature, ovoid, 14-17 3 10-11.5 mm, smooth to rugose, apex apiculate; dry pericarp 0.5-0.9 mm thick; endocarp woody; seed 9 3 6 mm.

Distribution, ecology and phenology

Noronhia densiflora occurs in littoral to low-elevation humid forests in the east, from Mananjary to Vangaindrano ( Fig. 9 ). It produces flowers and fruits from June to February.

Conservation status

The assessment, which used the 12 available collections representing 10 localities, indicated an EOO of 1,220 km 2, an AOO of 40 km 2, and seven subpopulations representing six locations, of which three occur within protected areas (Ankarabolava-Agnakatrika and Manombo). In recent years, Noronhia densiflora has been mostly collected from around Farafangana and Vangaindrano, but it is known to occur around Mananjary as well. However, the latter subpopulation was only sampled once in 1967 and the area is currently highly degraded as a result of slashand-burn agriculture and other forms of exploitation. With continuing decline in habitat quality and habitat loss, which also leads to loss of mature individuals, N. densiflora is therefore assigned a preliminary status of “Vulnerable” [VU B1ab(i,ii,ii i,iv,v)+2ab(i,ii,iii,iv,v)].

94 Boissiera 70

Notes

Noronhia densiflora differs from all other members of the genus by its somewhat lianescent habit when young, flaky bark, thickly coriaceous leaves measuring up to 75 cm long, compact intrapetiolar inflorescences, and globose red flowers.

Additional specimens examined

MADAGASCAR. Prov. Fianarantsoa: Farafangana, Anankara , Manombo RS, 23°22’47”S 47°35’59”E, 100-200 m, 16.IV.2000, Andrianjafy et al. 40 ( CNARP, MO, P) ; ibid. loc., [23°02’S 47°44’E], Friedmann 164 ( TAN) ; Anankara, Manombo AP, parcelle 2, 23°00’S 47°42’E, 5.III.2009, Hong-Wa 611 ( MO, P, TAN) ; Vangaindrano, Antavikazaha, Androkabe forest , 23°30’47”S 47°30’23”E, 77 m, 14. VI.2011, Letsara et al. 1122 ( CAS, MO) ; S of Farafangana, Manombo RS, 23°04’02”S 47°40’14”E, 50 m, 17.XI.2001, McPherson & Rabenantoandro 18442 ( MO, P) ; Marofototra, Ankarabolava, Letomanga , 23°30’15”S 47°29’10”E, 50 m, 5.IX.2010, Randrianarivony et al. 178 ( MO, P, TAN) ; Tsianofana, Tsararano , 23°26’47”S 47°30’31”E, 135 m, 19.X.2010, Razafitsalama et al. 1398 ( MO, P, TAN) ; S de Farafangana , route de Manombo, PK 20-21, 14-17.X.1964, Service Forestier 23602 ( P, TEF) ; ibid. loc., 17.X.1964, Service Forestier 23643 ( P, TEF) ; Mananjary, Ambodikijy , [21°13’S 48°21’E], 50 m, 25. II.1967, Service Forestier 26294 ( G, P, TEF) ; Manombo RS, 23°00’51”S 47°43’41”E, 30 m, 4. II.2006, Tosh 339 ( BR, MO, P, TAN) .

Figures

Fig. 15. Noronhia densiflora Bosser [Razafitsalama 1398].

Fig. 9. Distribution maps of species of Noronhia Stadtm.ex Thouars. N. christenseniana Dubard to N. domatifera Bosser.