Noronhia densiflora Bosser Noronhia disjuncta

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 : 93-98

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

Typus: M ADAGASCAR. 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)].

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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) .

Photo: C.Birkinshaw

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24. Noronhia disjuncta Hong-Wa, spec. nova ( Fig. 16).

Typus : MADAGASCAR. Prov. Antsiranana: DIANA, RNI No 4 Tsaratanana, Antsahamanara , Beangona , 14°02’06”S 48°47’08”E, 1400 m, 28.XI.2000, Randria et al. 16 (holo-: MO-6615569!; iso-: G [ G00341628 ]!, K!, P [ P00641023 ]!, TAN!) .

Diagnosis

Noronhia disjuncta Hong-Wa can be distinguished from its congeners by its light gray to whitish bark, its ovate leaf blades and its compact inflorescences with red flowers.

Description

Trees to 12 m tall, trunk to 17 cm diameter; young twigs cylindrical, 1.3-2.3 mm diameter, glabrous; bark light gray to whitish, smooth to somewhat rugose, with scattered lenticels. Leaves opposite, persistent; bud scales persistent; blades medium green above, lighter below, ovate to broadly elliptic, 8.5-13.5 3 3-5.5 cm, coriaceous, glabrous, domatia absent, base rounded to acute, margin flat to slightly undulate, apex acuminate, the acumen 4-9 mm long, midrib slightly sunken above, distinctly raised below, secondary veins mostly conspicuous below, 9-13 per side, 11-17 mm apart, looping 2.5-4.5 mm from the margin; petiole medium gray, 7-13 3 1.8-2.7 mm, entirely woody, glabrous. Thyrses geminate, multiflorous, compact; peduncle 6 mm long, moderately pubescent; pedicel 4-9 mm long, sparsely pubescent; calyx sparsely pubescent outside, glabrous inside, lobes triangular, 1.5 3 1-2 mm; corolla red outside, whitish inside, urceolate, 3-4.5 mm long, glabrous on both sides, the tube 1.5-2.7 mm long, lobes deltate, apex acute; corona present, 1.5-2.6 mm long, undivided; stamens 2-2.5 mm long, anthers obovate, 1.6 mm long; pistil 2.5-2.6 mm long, stigma capitate to slightly bilobed. Fruiting pedicel 4-13 3 1-2 mm; young fruits green, black when mature, subglobose to ovoid, 12.9-18.8 3 11.1-14.4 mm, surface smooth, apex flat to rostellate, the rostellum circular, obtuse, with the persistent style; dry pericarp 0.5-1.1 mm thick; endocarp woody; seed 7.6-12.2 3 6.4-8.7 mm.

Etymology

The specific epithet refers to the somewhat disjunct distribution of this species.

Distribution, ecology and phenology

Noronhia disjuncta occurs in mid- to high-elevation humid forests on basement rocks from Tsaratanana and Antalaha, in the north, to Ranomafana, in the south ( Fig. 9). It produces flowers and fruits from November to January.

Conservation status

Although Noronhia disjuncta is currently known only from nine collections representing nine localities, it has an EOO of 41,247 km 2, an AOO of 36 km 2, and six subpopulations representing six locations, all of which occur within protected areas (Anjanaharibe-Sud, Marojejy, Ranomafana, Tsaratanana, and Tsaratanana-Ambohi-

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mirahavavy-Corridor Marojejy). With all the collections made at high elevations within these protected areas, little to no threat is expected to affect this species in the near future. Therefore, N. disjuncta is assigned a preliminary status of “Least Concern”.

Notes

Noronhia disjuncta resembles both N. humblotiana (H. Perrier) Hong-Wa and N. mangorensis H. Perrier , but can be distinguished by its thyrsoid inflorescences (vs. fasciculate flowers in both of the other species), smooth (vs. rugose) fruit surface, and flat to rostellate (vs. apiculate) fruit apex. The new species can be recognized by its light gray to whitish bark, ovate leaf blades, and compact inflorescences with red flowers.

Paratypi

MADAGASCAR. Prov. Antsiranana: Marojejy PN , 14°28’57”S 49°38’12”E, 1100- 1600 m, 19-24. I .1994, Malcomber et al. 2701bis ( MO, TAN); Andapa, Ambodisatrana , 14°32’S 49°26’E, 1000-1100 m, 2.VIII.1997, McPherson 17165 ( MO, TAN); Bealampona , Anjanaharibe-Sud RS , 14°44’45”S 49°29’40”E, 890-1041 m, 14.IX.1994, Ravelonarivo et al. 377 ( MO, P, TAN); ibid. loc. , 14°43’42”S 49°27’57”E, 1570 m, 1.XII.2003, Schmidt 4377 ( MO). Prov. Fianarantsoa: Ranomafana PN , 21°15’S 47°27’E, 1100 m, 11-15.XI.1991, Malcomber et al. 1077 ( G, MO, P, TAN); ibid. loc. , 21°16’S 47°26’E, 1000-1100 m, 18-31. I .1993, Malcomber et al. 2034 ( MO, P); ibid. loc. , 21°15’30”S 47°25’00”E, 950-1150 m, 21. I .1993, Turk & Randrianasolo 255 ( G, MO, P, TAN). Prov. Mahajanga: Tsaratanana Massif , 1800-2000 m, 11. V .1974, Gentry 11688 ( MO, P, TAN) .