Abrahamia lokobensis 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 : 93-94

19. Abrahamia lokobensis Randrian. & Lowry , spec. nova ( Fig. 16 ).

Typus: MADAGASCAR. Prov. Antsiranana: Rég. Diana , RNI Lokobe , 13°24’40’’S 48°18’50’’E, 40-80 m, 24.XI.1994, fr., Antilahimena 198 (holo-: MO- 6671433 !; iso-: G!, K!, NY!, P [ P06775168 ]!, TAN [ TAN001991 ]!).

Diagnosis

Abrahamia lokobensis Randrian. & Lowry can be distinguished from its congeners by its large (14.6-23.9 3 4.8-7.2 cm), chartaceous to subcoriaceous, oblanceolate leaves and its obovoid fruit borne in a terminal infructescence.

Description

Trees c. 8-25 m tall, 10-80 cm DBH, bark with white latex; young twigs lenticellate, glabrous. Leaves opposite to subopposite or alternate; blade oblanceolate, 14.6-23.9 3 4.8-7.2 cm, chartaceous to subcoriaceous, apex short acuminate, retuse or sometimes emarginate, margin entire, base cuneate, sometimes asymmetric, adaxial surface glabrous, abaxial surface nearly glabrous except sparsely scabrous indument on midvein or around it, venation craspedodromous, midvein prominent abaxially, secondary veins c. 30-45 pairs, 2-10 mm apart, forming wide angle with the midvein, raised on both surfaces, tertiary veins visible on both surfaces; petiole 13-30.5 mm long, 1.5-3 mm in diam., canaliculate on adaxial surface, very often pubescent, glabrescent or sometimes glabrous. Inflorescence terminal or pseudoterminal, a panicle, 2.5 3 7 cm, with buds at very early stage of development, dark brown pubescent. Flowers unknown. Fruits 2-3.1 3 1-1.5 cm, obovoid, pale green, glabrous, with longitudinal striations.

Distribution, ecology and phenology

Abrahamia lokobensis is only known from northwestern Madagascar; it occurs at elevations between 10 and 100 m at the Lokobe reserve on the island of Nosy-be, and up to 1200-1400 m in Tsaratanana national park ( Map 5 ). Flowers have been collected in August and fruits in November.

Conservation status

Abrahamia lokobensis has an EOO of 3,124 km 2 and a minimum AOO of 16 km 2, with two subpopulations occurring within a protected area (Lokobe and Tsaratanana) whereas the other subpopulation was collected in the area of Maromandia where future decline is expected in terms of quality of habitat, and thus exists at three locations with respect to the threat of habitat degradation. It has therefore been assigned a preliminary status of “Endangered” [EN B1ab(iii)+2ab(iii)] using the IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes

Abrahamia lokobensis most closely resembles A. sambiranensis but can be distinguished by its smaller number of secondary veins (35-45 vs 50-60), its tertiary venation that is visible on both leaf surfaces (vs not visible), its shorter petiole (13-19 vs (20-) 25-65 mm), and exclusively terminal (vs axillary) infructescence.

94 Boissiera 71

Paratypi

MADAGASCAR. Prov. Antsiranana: Rég. Diana, Lokobe RNI, 13°25’S 48°18’E, 10-100 m, 14.XI.1996, fr., Antilahimena et al. 315 ( G, K, MO, P, TAN) ; ibid. loco, [13°25’S 48°19’E], 13-15.III.1964, fr., Service Forestier 23459 ( MO, P) ; Maromandia, Ambanja , [14°12’S 48°05’E], 15.VIII.1952, ster., Service Forestier 64-R-152 ( P [2 sheets]) ; Tsaratanana RNI, Ambinany Beangona , 14°01’S 48°47’E, 1200-1400 m, 1.VIII.2000, y. bud, Antilahimena et al. 533 ( G, K, MO, NY, P, TAN).

Figures

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

Fig. 16. C Abrahamia lokobensis Randrian. & Lowry. A. Fruiting branch; B. Fruit; C. Inflorescence with buds.