Abrahamia oblongifolia (Engl.) Randrian. & Lowry

Randrianasolo, Armand, Lowry II, Porter P. & Schatz, George E., 2017, Taxonomic treatment of Abrahamia Randrian. & Lowry, a new genus of Anacardiaceae from Madagascar, Boissiera 71, pp. 1-152 : 107-108

24. Abrahamia oblongifolia (Engl.) Randrian. & Lowry , comb. nova.

≡ Protorhus oblongifolia Engl. in Bot. Jahrb. Syst. 1: 422. 1881.

Typus: MADAGASCAR. Prov. Antsiranana: Rég. Diana , Nossi-Bé , 1840, fl., Richard 366 (holo-: P [ P00722663 ]!).

Description

Trees 10-20 m tall, 23-25 cm DBH; young twigs very often triangular, lenticellate, with ferruginous indument. Leaves subopposite to opposite; blades obovate to oblanceolate or narrowly oblong to elliptic, 4-17 3 1.5-5.5 cm, chartaceous to subcoriaceous, apex retuse, rounded, or emarginate, margin entire, minutely thickened and pale in color on abaxial surface, base cuneate or cuneate-obtuse, adaxial surface glabrous, somewhat waxy, abaxial surface pubescent when young, later nearly glabrous, venation craspedodromous (rarely a few secondary veins not quite reaching the margin), midvein prominent abaxially, secondary veins 35-40 pairs, 2-6 mm apart, more or less parallel, prominent on both surfaces but more so abaxially, tertiary veins slightly raised on abaxial surface; petiole 5-15 mm long, canaliculate on adaxial surface, glabrous, waxy. Inflorescence axillary or terminal, a panicle, 3-5 cm long, the axes terete or flattened, with ferruginous indument. Male and female flowers 5-merous (rarely 6-merous); pedicel 0-0.5 mm long, ferruginous pubescent or strigose; calyx lobes ovate, c. 1 3 1 mm, imbricate, adaxial surface glabrous, abaxial surface pubescent or ferruginous pubescent; corolla lobes ovate, 2 3 1 mm, imbricate, adaxial surface glabrous, abaxial surface ferruginous pubescent or scabrous; stamens 5 or 6. Male flowers with filaments 1-1.5 mm long, glabrous, anthers c. 0.5 mm long, subglobose, glabrous; disk cupuliform, sometimes shallowly so, 1-1.5 mm in diam., glabrous; ovary rudimentary. Female flowers with filaments 0.5-0.7 mm long, glabrous, anthers c. 0.3 mm long, subglobose to slightly ovoid, glabrous; disk annular, cupuliform, sometimes shallowly so, 1.5 mm in diam., sterile, glabrous; ovary very widely ovoid, slightly asymmetric, 1 3 1 mm, glabrous, placentation apical; style simple, very short, inserted more sub-apically than laterally, 1 mm long, glabrous, stigma capitate, 3-4-lobed. Fruits c. 2 3 1 cm, ellipsoid, slightly asymmetrical, glabrous, with obscure longitudinal striations.

Vernacular names

“Hazombarorana’’, “Manavodrevo’’, “Tarata’’, “Tsiramiramy’’.

Distribution, ecology and phenology

Abrahamia oblongifolia occurs in far northern and northwestern Madagascar ( Map 6 ), from sea level to an elevation of c. 300 m, usually along rivers or at the base of hills or mountains. Flowering material has been recorded in October and November, and fruits have been collected in December and January.

Conservation status

With an EOO of 3,220 km 2, a minimum AOO of 32 km 2, and estimated maximum AOO of <500 km 2, and 7 recorded localities representing 7 locations with respect to the threat of forest exploitation, and with subpopulations in 2 protected areas (Analamera and Montagne des Français) and projected decline outside of protected areas, A. oblongifolia is assigned a preliminary conservation status of “Vulnerable’’ [VU B1ab(iii)+2ab(iii)] using the IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes

Abrahamia oblongifolia can be distinguished from all other members of the genus by the combination of its numerous secondary veins (35-40), both terminal and axillary inflorescences, and glabrous fruits.

Additional material examined

MADAGASCAR. Prov. Antsiranana: Analamera RS, Betsieka , [12°42’S 49°20’E], 10-20 m, I.1938, ster., Humbert 19091ter ( P) ; Mahavanona, Montagne des Français, Ambatosarolo , 12°22’27’’S 49°21’26’’E, 204 m, 8.X.2004, y. fr., Randriambololomamonjy et al. 42 ( MO, P, TAN) ; Sakaramy , près de Diego, [12°27’S 49°13’E], bud, Perrier de la Bâthie 17672 ( P) ; Ramena, Montagne des Français, Andavakoera , 12°20’48’’S 49°21’28’’E, 88 m, 7.IX.2004, fl., Randrianaivo 1081 ( CNARP, G, MO, P, TAN, TEF) ; Mahavanona, Montagne des Français, campement Antafiankoroka , 12°21’39’’S 49°21’34’’E, 281 m, 24.IX.2004, y. fr., Randrianarivelo et al. 139 ( G, K, MO, P, TAN) ; Nosy Be , [13°19’S 48°16’E], 1840, fr., Richard 315 ( P) ; Montagnes des Français , [12°22’S 49°21’E], 31.XI.1952, bud, Service Forestier 5885 ( MO, P [2 sheets], TEF) ; ibid. loco, 23.XI.1955, bud, Service Forestier 15355 ( G, MO, P [2 sheets], TEF) ; Forêt de Sahankazo , [12°29’S 49°26’E], 11.XII.1955, fr., Service Forestier 15507 ( G, MO, P [2 sheets], TEF) ; Montagnes des Français , [12°22’S 49°21’E], 21.IV.1954, ster., Service Forestier 28-R-61 ( P) ; ibid. loco, 21. V.1951, ster., Service Forestier 51-R-150 ( P) ; ibid. loco, 24.III.1955, ster., Service Forestier 442-R-6 ( P) . Sine loco: 17.X.1927, fl., Ursch 186 ( P).

Figures

Map 6. Geographic distribution of species of Abrahamia Randrian.& Lowry