Abrahamia itremoensis Randrian. & Lowry, 2017

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 : 76-77

14. Abrahamia itremoensis Randrian. & Lowry , spec. nova ( Fig. 12 ).

Typus: MADAGASCAR. Prov. Fianarantsoa: Itremo, W of Itremo village, slope NE of the waterfall, 20°35’S 46°36’E, 1450 m, 6.X.1996, fl., A. Randrianasolo 491 (holo-: MO-4895266!; iso-: P [ P06169070 ]!, TAN [ TAN001990 ]!) .

Diagnosis

Abrahamia itremoensis Randrian. & Lowry differs from the species it most closely resembles, A. buxifolia , by its leaves that are pubescent (vs glabrous) and the presence of indument on the disk in male flowers (vs glabrous).

Description

Shrubs or small trees 0.3- 4 m tall. Leaves opposite or subopposite; blades oblanceolate, 2-6 3 0.6-2 cm, coriaceous, apex rounded, sometimes retuse or slightly emarginate, margin entire, base cuneate to slightly obtuse, adaxial surface puberulous, abaxial surface pubescent, venation craspedodromous, midvein prominent abaxially, secondary veins 18-26 pairs, parallel, 0.5-1 mm apart, prominent on both surfaces, tertiary veins weakly visible on upper surface, completely invisible on lower surface, petiole short, 1-3 mm long, canaliculate on adaxial surface, pubescent. Inflorescence axillary or terminal, a panicle, short, c. 1-2.5 cm, pubescent; bracts triangular to deltate, c. 1-2 3 0.5-0.8 mm. Male flowers small, 5-merous, 2-4 mm long; pedicel very short, c. 0.1-0.2 mm, pubescent; calyx lobes triangular to deltate, c. 1-1.5 3 1 mm, imbricate, adaxial surface glabrous, abaxial surface pubescent; corolla lobes ovate to oblong, c. 2-4 3 1-2 mm, imbricate, adaxial surface glabrous, abaxial surface pubescent; stamens 5, filaments c. 1 mm long, pubescent, anthers c. 1 3 0.3-0.4 mm, oblong to slightly ovoid, glabrous; disk c. 1 mm in diam., cupuliform, pubescent; ovary rudimentary. Female flowers unknown. Fruits 1.5-2.3 3 1.2-1.5 cm, obovoid to ellipsoid, velutinous.

Distribution, ecology and phenology

Abrahamia itremoensis occurs mainly at Itremo and in the surrounding area ( Map 5 ), at elevations between 1000 and 1800 m. It grows on rocky soil in areas that are regularly subjected to fire. Flowering material has been collected in October and specimens with fruit have been gathered between January and April.

Conservation status

With an EOO of 154 km 2, a minimum AOO of 32 km 2, and 6 known locations, most of which are situated within a newly established protected area (Itremo) but are still subjected to fire and possible degradation leading to a projected decline in quality of habitat, A. itremoensis 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 itremoensis can be confused with A. minutifolia due to its small, coriaceous leaves with craspedodromous venation, and it velutinous fruits, but it clearly differs by its oblanceolate (vs obovate) leaf blades, its paniculate (vs thyrsiform) inflorescence, and its larger fruits (1.5-2.3 3 1.2-1.5 vs 1-1.5 3 0.5-0.8 cm).

One of the collections assigned to this species, Decary 13041, was cited in the protologue of Protorhus buxifolia H. Perrier and therefore represents a syntype of that name.

Paratypi

MADAGASCAR. Prov. Fianarantsoa: Ambatofinandrahana, Itremo , SW d’Antsirakambiaty , 20°36’34’’S 46°33’30’’E, 1688 m, 10.XII.2003, fr., Andriamihajarivo 251 ( G, MO, P, TAN) ; Itremo, Andaobatofotsivava , 20°37’54’’S 46°35’53’’E, 1387 m, 21.XII.2003, fr., Antilahimena et al. 2465 ( MO, P, TAN) ; col d’Itremo, 2 km from Vodiharana , 3.VIII.1984, ster., Baum 47 ( MO, TAN) ; Itremo , [20°32’S 46°33’E], 1700 m, IX.1956, bud, Bosser 10074 ( TAN [2 sheets]) ; ibid. loco, X.1963, bud, Bosser 18107 ( MO, P, TAN) ; env. d’Ambatofinandrahana , [20°33’S 46°48’E], 1600-1800 m, 17.II.1938, fr., Decary 13041 ( P) ; W d’Itremo , [20°36’S 46°39’E], 1500-1700 m, 17-22. I. & 18-22.IV.1955, fr., Humbert 28151 ( MO, P) ; Itremo , 20°34’40’’S 46°34’53’’E, 1550 m, 29.X.1997, fl., Malcomber et al. 2841 ( G, MO, P, TAN) ; forêt d’Ianasana , 7 km W d’Itremo, 20°36’S 46°34’E, 1630 m, 5.II.1999, fr., Messmer et al. 794 ( G, MO, P, TAN) ; Itremo , [20°32’S 46°33’E], X.1964, fl., Morat 905 ( P, TAN) ; Ambatofinandrahana , [20°33’S 46°48’E], 15.X [no year given], bud, Rauh 813 ( TAN) ; Mt. Ambatomenaloha, W d’Itremo , [20°32’S 46°33’E], 20. I.1955, fr., Service Forestier 11576 ( P, TEF) ; env. du col d’Itremo ( W d’Ambatofinandrahana ), [20°32’S 46°33’E], 1600-1700 m, 27.XI.1969, y. fr., Service Forestier 28897 ( P, TEF) ; Ambatofinandrahana, massif d’Itremo , 20°37’S 46°35’E, 1500 m, 27.X.1994, fl., van der Werff 13563 ( G, MO, P, TAN).

Figures

Map 5. Geographic distribution of species of Abrahamia Randrian.& Lowry

Fig. 12. Abrahamia itremoensis Randrian. & Lowry. A. FLowering branch; B. Leaf (adaxiaL surface); C.Leaf (abaxiaL surface);D. ULtimate inflorescence unit with 3 flowers E. Inflorescence.