Noronhia humbertiana H. Perrier

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 : 122-124

33. Noronhia humbertiana H. Perrier in Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 2: 295. 1949 ( Fig. 24 ).

Typus: MADAGASCAR. Prov. Antsiranana: Collines et plateaux calcaires de l’Ankarana, à l’O d’Ambondrofe , [12°54’S 49°09’E], 300 m, XII.1937 - I.1938, Humbert 18948 (holo-: P [ P00418108 ]!; iso-: K [ K000233190 ] image seen, P [ P00418109 , P00418110 ]!, S [ S09-36003 ] image seen, WAG [ WAG0002491 ] image seen).

Description

Trees to 8 m tall, trunk to 20 cm in diam.; young twigs cylindrical, 0.7-4.2 mm in diam., pubescent; bark greenish, rugose, somewhat flaky. Leaves opposite, deciduous; bud scales persistent; blades medium green above, yellowish below, oblong to lanceolate, 6.5-23 3 3-9 cm, chartaceous, pubescent on lower midrib, domatia casual, base rounded to acute, margin undulate, apex acuminate, the acumen 3-22 mm long, midrib slightly sunken above, raised below, secondary veins conspicuous, 7-14 per side, 7-25 mm apart, looping 1.5-9 mm from the margin; petiole yellowish green, 7-20 3 1.2-2.4 mm, usually not woody, pubescent. Thyrses geminate to fasciculate, pauciflorous, somewhat compact; peduncle 11-14 mm long, densely pubescent; pedicel 4-6 mm long, densely pubescent; calyx densely pubescent outside, only sparsely inside, lobes triangular, 5-9 3 1.8-2 mm; corolla reddish brown outside, yellowish inside, campanulate, 17-22 mm long, glabrous on both sides, the tube 9-12 mm long, lobes ovate to triangular, apex acute; corona present, 1.8-2 mm long, undivided; stamens 2-2.2 mm long, anthers widely oblong to somewhat square or cordiform, 1.5 mm long; pistil 1.8-2 mm long, stigma bilobed. Fruiting pedicel 5-22 3 1-2.6 mm; young fruits green, brownish when mature, subglobose, 13-23.5 3 11.5-21 mm, surface smooth, sometimes covered with white dots, apex flat to rostellate, the rostellum flattened, ridged, truncate; dry pericarp 1.6-2.9 mm thick; endocarp woody; seed 7.5-10 3 4-9 mm.

Distribution, ecology and phenology

Noronhia humbertiana occurs in low-elevation dry forests in northern Madagascar, from Ankotekona to south of Vohémar ( Fig. 19 ). It produces flowers and fruits throughout the year.

Conservation status

Using 19 collections representing 17 localities, the assessment yielded an EOO of 5,633 km 2, an AOO of 60 km 2, and 14 subpopulations representing 10 locations, of which four occur within protected areas (Andavakoera-Andrafiamena-Ambohipiraka, Ankarana, Loky-Manambato, and Montagne d’Ambre). Except for those overlapping with protected areas, most of the habitats for N. humbertiana show signs of degradation that result from land conversion, leading also to habitat loss and reduction of the number of mature individuals. Consequently, N. humbertiana is assigned a preliminary status of “Vulnerable” [VU B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)].

Photo: L. Nusbaumer

124 Boissiera 70

Notes

Noronhia humbertiana can be recognized by its pubescent leaves, large campanulate flowers measuring up to 2.5 cm long, and subglobose to globose fruits with large sepals. It is the only species of Noronhia with such large flowers.

Additional specimens examined

MADAGASCAR. Prov. Antsiranana: Mosorolava, forêt d’Antsoroby , 12°42’38”S 48°58’16”E, 58 m, 26.IX.2007, Andriamihajarivo et al. 1411 ( MO, P, TAN) ; Ankarana RS, 13°00’46”S 49°03’03”E, 11-14 m, 7. V.1996, Andrianantoanina & Bezara 973 ( G, K, MO, P) ; Ambohitsitondroina , 13°07’38”S 49°28’16”E, 100 m, 15.III.2004, Gautier et al. 4584 (Daraina, G, K, MO, P, TEF) ; Daraina, forêt d’Antsaharaingy , 12°53’07”S 49°40’06”E, 25 m, 18.XI.2006, Gautier & Chatelain 4851 (Daraina, G, K, MO, P, TEF) ; Tanambao-Marivorahona , 13°02’34”S 49°09’14”E, 45 m, 2.VII.2005, Guittou et al. 156 ( CNARP, MO, P, TAN) ; Vohémar, Ampisikinana, forêt d’Ampondrabe , 12°58’13”S 49°41’56”E, 200 m, 3.XI.2005, Guittou et al. 198 ( CNARP, G, MO, P, TAN) ; Sakaramy , Montagne d’Ambre PN, 12°26’40”S 49°13’56”E, 300 m, 29. V.2010, Hong-Wa 695 ( MO, P, TAN) ; Daraina, forêt d’Ambohitsitondroina , 13°09’07”S 49°27’38”E, 177 m, 11. I.2006, Nusbaumer & Ranirison 1895 (Daraina, G, K, MO, P, TEF) ; Daraina, Andranovaka, Ankijomantsina , 13°07’56”S 49°28’20”E, 75 m, 29.X.2005, Rakotonandrasana et al. 935 ( CNARP, G, MO, P, TAN) ; Marivorahona, Betsimiranja , forêt d’Andohan’Antsohihy, 13°02’31”S 49°09’19”E, 100 m, 17.VII.2005, Randrianaivo et al. 1204 ( CNARP, MO, P, TAN) ; Daraina, forêt d’Ambohitsitondroina , 13°07’50”S 49°28’05”E, 150 m, 8. I.2006, Ranirison & Nusbaumer 1059 (Daraina, G, K, MO, P, TEF) ; Vohémar, Ankaramy , [13°32’30”S 49°48’00”E], 100 m, 26.VIII.1955, Service Forestier 14710 ( P, TEF) ; Ankotekona , [12°20’S 49°05’E], 18. V.1956, Service Forestier 15921 ( P, TEF) ; Ankarana, près de Marotaolana ( Anivorano-Nord ), [12°44’S 49°14’E], 25.XII.1963, Service Forestier 23119 ( G, P, TEF) ; S de Marotaolana ( Anivorano-Nord ), [12°44’S 49°14’E], 23.XII.1963, Service Forestier 23125 ( P, TEF) .

Figures

Fig. 24. Noronhia humbertiana H. Perrier [Nusbaumer 1895].

Fig.19. Distribution maps of species of Noronhia Stadtm.ex Thouars.N.edentata (H.Perrier) Hong-Wa to N.insularis (Labat,M.PignaL & O. PascaL) Hong-Wa & Besnard.