Noronhia linearifolia 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 : 148-149

43. Noronhia linearifolia H. Perrier in Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 2: 289. 1949.

Typus: M ADAGASCAR. Prov. Antsiranana : N de Madagascar, baie de Rigny, Port Lewen , [12°45’S 49°43’E], III-IV.1849, Boivin 2451 (holo-: P [ P00608381 ]!; iso-: P [ P00608382 ]!) .

Description

Shrubs to small trees to 6 m tall, trunk to 7 cm diameter; young twigs cylindrical, 0.6-1.3 mm diameter, glabrous; bark medium gray, smooth to slightly rugose. Leaves opposite, persistent; bud scales persistent; blades medium green above, lighter below, linear, 3-8 3 0.5-1.3 cm, coriaceous, glabrous, domatia absent, base rounded, margin revolute, apex retuse (rarely mucronulate), the mucro 1-2.5 mm long, midrib flat to slightly sunken, raised below, secondary veins inconspicuous, 5-13 per side, 3-12 mm apart, looping 0.5- 1.6 mm from the margin; petiole medium gray, 1.5-6 3 0.2-1.4 mm, entirely woody, glabrous. Flowers solitary; pedicel 2.5-5.5 mm long, glabrous; calyx sparsely pubescent outside, glabrous inside, lobes widely ovate, 1.1-1.8 3 1-2.1 mm; corolla reddish-brown tinged white, urceolate, 3.8-7 mm long, glabrous on both sides, the tube 3-5.5 mm long, lobes ovate, apex rounded; corona present, 1-2 mm long, lobed; stamens 1.7-2.4 mm long, anthers ovate, 1.3-1.8 mm long; pistil 2-3 mm long, stigma capitate. Fruiting pedicel 2-8 3 0.8-1.6 mm; young fruits green, reddish black when mature, ovoid, 7-14 3 5-11 mm, smooth, sometimes covered with a white pellicle, apex flat to apiculate; dry pericarp 0.5-1.9 mm thick; endocarp woody; seed 6.5-9.5 3 4-5.5 mm.

Distribution, ecology and phenology

Noronhia linearifolia occurs in littoral to low-elevation dry forests in the north, from Orangéa (Oronjia) to Vohémar ( Fig. 27 ). It produces flowers and fruits throughout the year except in March and April.

Conservation status

The assessment was based on 21 collections representing 18 localities and resulted in an EOO of 1,825 km 2, an AOO of 56 km 2, and 12 subpopulations representing 10 locations, of which five occur within the network of protected areas (Analamerana, Loky-Manambato, Montagne des Français, and Oronjia). Conversion of land into agricultural fields and pastures, wood harvesting, charcoal production, and in some cases gradual sea level rise constitute threats to some of the subpopulations, thereby reducing the EOO, AOO, habitat quality and number of mature individuals. Thus, N. linearifolia is assigned a preliminary status of “Vulnerable” [VU B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)].

Notes

Noronhia linearifolia can be recognized by its coriaceous, linear leaf blades with barely visible venation and its solitary, red flowers. It differs from N. alleizettei by its linear (vs. narrowly elliptic) leaf blades, solitary (vs. fasciculate), reddish brown (vs. white) flowers, and the presence (vs. absence) of a corona.

Additional specimens examined

MADAGASCAR. Prov. Antsiranana: Analabolona, 3 km à l’W d’Irodo , 12°37’21”S 49°30’01”E, 102 m, 20.VII.2004, Be et al. 15 ( CNARP, MO, P, TAN) ; Andrafiabe, Ambolobozokely, Ampasimena , 12°26’00”S 49°30’13”E, 35 m, 29.XII.2008, Christian et al. 83 ( CNARP, G, MO, P, TAN) ; Analamerana RS, 12°40’25”S 49°32’40”E, 41 m, 8. I.2002, De Block 1128 ( BR, G, K, MO, P, TAN, WAG) ; Ramena, Andavakoera , 12°19’57”S 49°21’19”E, 172 m, 4.VIII.2007, Hong-Wa 526 ( CNARP, MO, P, TAN) ; Analamera , [12°47’24”S 49°30’00”E], 50-400 m, I.1938, Humbert 19114 ( P) ; 40 km N of Vohémar, near N end of Lac Sahaka , 13°04’45”S 49°54’17”E, 20 m, 3.XI.2002, McPherson 18876 ( MO, P, TEF) ; Orangéa , 12°15’01”S 49°21’39”E, 50 m, 20. I.2003, Miller et al. 10727 ( G, MO) ; Vohémar, Anjiabe, Analabe , 13°04’50”S 49°54’07”E, 9.VII.2003, Rabehevitra et al. 208 ( MO, P, TEF) ; Ramena, forêt d’Orangéa , 12°14’45”S 49°21’20”E, 13-25 m, 4.IX.2001, Rabenantoandro & Razanatsoa 631 ( MO, P, TAN) ; Vohémar, Anjiabe, forêt d’Anaborano près du Lac Sahaka , 13°04’42”S 49°54’13”E, 25 m, 2.XI.2002, Rabenantoandro et al. 1103 ( MO, P, TAN) ; ibid. loc., 13°04’43”S 49°54’04”E, 10 m, 23. II.2003, Rabenantoandro et al. 1280 ( G, MO, P) ; Ambolobozobe, Ankonahona , 12°31’S 49°32’E, 27.XI.2007, Rakotonandrasana et al. 1249 ( CNARP, MO, TAN) ; Baie de Sakalava , 12°16’39”S 49°22’49”E, 21 m, 5.XI.2006, Ranaivojaona et al. 1506 ( G, MO, P, TAN) ; Vohémar, Anjiabe, Anaborano , forêt d’Analabe , 13°04’09”S 49°54’08”E, 18 m, 21.VII.2004, Randrianarivelo & Sola 74 ( MO, P, TAN) ; Andrafiabe, Sahafary , 12°35’43”S 49°26’54”E, 233 m, 11.IX.2004, Razafitsalama et al. 635 ( CNARP, MO, P, TAN)

Figures

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