Abrahamia revoluta 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 : 117

28. Abrahamia revoluta Randrian. & Lowry , spec. nova ( Fig. 25 ).

Typus: MADAGASCAR. Prov. Antsiranana: Rég. SAVA , Vohémar, forêt littoral au S de Vohémar, [13°21’S 50°00’E], 1-19.XII.1966, fr., Service Forestier 24318A (holo: P [ P06168913 ]!; iso-: MO- 05056713 !).

Diagnosis

Abrahamia revoluta Randrian. & Lowry can be distinguished from its congeners by its glabrous leaves with undulate and revolute margins and semicraspedodromous secondary veins.

Description

Trees 15-20 m tall, 21.6 cm DBH; young twigs glabrous, lenticellate. Leaves opposite or subopposite; blade obovate, 3.2-9 3 1.4-3.8 cm, subcoriaceous, apex retuse, sometimes emarginate, margin revolute, undulate, base cuneate, both surfaces glabrous, venation semicraspedodromous, midvein prominent abaxially, secondary veins 15-30 pairs, more or less parallel, 2-4(-5) mm apart, raised on both leaf surfaces, tertiary veins not visible on both surfaces; petiole 5-13 mm long, 0.5-1 mm in diam., canaliculate on adaxial surface, usually glabrous. Inflorescence and flowers unknown. Infrutescence terminal. Fruits 2.5-2.7 3 1.3-1.5 cm, glabrous, with longitudinal striations.

Distribution, ecology and phenology

Abrahamia revoluta occurs in NE Madagascar from S of Vohémar to the southern part of the Masoala peninsula ( Map 9 ). Fruiting material has been gathered between October and December.

Conservation status

Abrahamia revoluta has a minimum AOO of 12 km 2 and only one of its three extant subpopulation occurs within a protected area (Masoala) whereas the other two were collected in areas where future decline is expected in terms of quality of habitat. It has therefore been assigned a preliminary status of “Endangered’’ [EN B2ab(iii)] using the IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes

Abrahamia revoluta most closely resembles A. ditimena , with which it shares obovate leaves with a retuse apex that are similar in size and the number of secondary veins. However, A. revoluta differs by its subcoriaceous (vs coriaceous) leaves, semicraspedodromous (vs craspedodromous) venation, revolute and undulate (vs entire and flat) leaf margins, obscure (vs raised and visible) tertiary venation on the lower leaf surface, terminal (vs terminal or axillary) infrutescences, and glabrous (vs velutinous) fruits.

Paratypi

MADAGASCAR. Prov. Antsiranana: versant NW de la Montagne d’Ambre , forêt d’Ankarefo (Ankazobe), 19-21.X.1954, y. fr., Service Forestier 11357bis ( P, MO). Prov. Toamasina: Maroantsetra , Masoala Peninsula, S of Ambanizana, 15°40’24’’S 49°57’51’’E, 110- 260 m, 29.XI.1994, ster., Vasey et al. 176 ( MO, TAN).

Figures

Map 9. Geographic distribution of species of Abrahamia Randrian.& Lowry

Fig. 25. Abrahamia revoluta Randrian. & Lowry. A. Fruiting branch; B. Fruit. [Service Forestier 24318A, MO] Drawings:R.L. Andriamiarisoa