Eugenia ravelonarivoi N. Snow & Callm., 2015

Snow, Neil, Callmander, Martin & Phillipson, Peter B., 2015, Studies of Malagasy Eugenia - IV: Seventeen new endemic species, a new combination, and three lectotypifications; with comments on distribution, ecological and evolutionary patterns, PhytoKeys 49, pp. 59-121 : 78-79

Eugenia ravelonarivoi N. Snow & Callm. sp. nov. holotype (Figure 18): http://www.tropicos.org/Image/100314919

Haec species a congeneris madagascariensibus foliis apice abrupte cupidatis caudatisve atque inflorescentiis ramifloris dense fasciculatis distinguitur.

Type.

MADAGASCAR. Prov. Antsiranana: SW d’Andapa, Réserve Spéciale Anjanaharibe-Sud, suivant la piste pour Ambalaheva, haute rivière d’Andramonta, 14°36'40"S, 49°24'12"E, 628-1879 m, 22 Feb. 1996, D. Ravelonarivo et al. 930 (holotype: MO-6135426!; isotypes: KSP [KSP000007, KSP000008]!, P [P04885351]!, TAN).

Description.

Shrubs or trees, 3-12 meters; bark of main bole unknown. Herbage glabrous except as noted. Branchlets laterally comprssed and shallowly 2-grooved on each side when young below petioles, oil glands common but indistinct, epidermis smooth, green drying light brown. Leaves evenly distributed along branchlets, opposite to disjunct opposite, thinly coriaceous to thickly membranous, discolorous, surfaces matte. Axillary colleters absent. Petioles 7-10 mm, narrowly and deeply sulcate (especially distally). Leaf blades (5.5-)7.5-14 × 3.3-4.8 cm, mostly elliptic but some broadly elliptic or narrowly oblong, base cuneate, apex obtuse, or acuminate and often falcate, margins flat but slightly undulate (dried); adaxial surface midvein deeply but narrowly sulcate to nearly the apex, secondary veins numerous but faint, oil glands absent; abaxial surface lakcking oil glands, secondary veins faint, slightly raised, diverging at ca. 80°; intramarginal vein 0.5-1.5 mm from margin at midpoint of blade. Inflorescences of moderately dense fascicles of monads arising from short brachyblasts, these evidently ramiflorous or cauliflorous (uncertain given that all are detached on herbarium sheets); pedicels 9-15 mm, rigid, irregularly glandular. Bracteoles 2, ca. 0.5-0.8 mm, triangular to ovate, often obscure. Hypanthium ca. 2-2.5 mm, cupuliform to discoid (somewhat flattened) in anthesis, prominently glandular. Calyx lobes 4, 2.0-5.0 mm, broadly oblong to oblate or rounded, often dimorphic (2 shorter, 2 longer), apex broadly rounded, petaloid, oil glands sparse (and mostly abaxial). Petals 4 (material scant), up to 5 mm; indicated as pinkish on a paratype. Staminal ring more or less square, ca. 4 mm per side, sparsely short hairy (use magnification) and glandular. Stamens (material scant) numerous; anthers ca. 0.5 mm, ellipsoid. Styles 6-11 mm, thin, sparsely glandular (especially proximally); stigma narrow. Berries 24-35 × 30-50 mm (dried), subglobular, greenish (mature or nearly so); seeds 1-3, 16-22 × 25-30 mm, subglobular; embryo globular, hypocotyl and cotyledons not differentiated; testa thinnish, drying light brown.

Phenology.

Flowering January through April; fruiting March through November.

Distribution.

In the northern mountains of Madagascar in Antsiranana and Mahajanga provinces (Fig. 4).

Habitat and ecology.

In mid-elevation, wet eastern forests often over granite or gneiss; elevation approximately 630-1880 m but needing confirmation.

Etymology.

It is a pleasure to name this species in honor of Désiré Ravelonarivo (b. 1966), a prolific collector of specimens in Madagascar. Désiré is native to the An dapa basin, where he collected the type specimen of Eugenia andapae and the only known fruiting specimen of this new species (D. Ravelonarivo 489 & R. Babesonina).

Vernacular name.

Gavoalehely (Ravelonarivo 930); gavoala (Ravelonarivo 103).

Conservation status.

With an EOO of 436 km2, an AOO of 36 km2 and three subpopulations, two of which are situated within the protected area network (Anjanaharibe-Sud), Eugenia ravelonarivoi is assigned a preliminary risk of extinction of “Vulnerable” [VU D2] following the IUCN Red List Categories and Criteria ( IUCN 2012).

Comments.

The label of the type gathering indicates “rougeâtres” (reddish) for petals, but this is doubtful and probably was meant for pinkish, which accords with information on the label of a paratype.

Among existing species, the leaf morphology of Eugenia ravelonarivoi resembles that of Eugenia alatroensis H. Perrier and Eugenia vatomandrensis H. Perrier, but the bases of their leaves are subsessile to sessile, which contrasts with the distinctly petiolate leaves of Eugenia ravelonarivoi . In addition, the often cuspidate-caudate aspect of the leaf apex of new species is much more pronounced than of those two species, whose tips are barely (if at all) cuspidate.

Eugenia antongilensis H. Perrier has cuspidate apices on the blade, but it is a much longer leaf with shorter petioles. Eugenia musicola H. Perrier also resembles Eugenia ravelonarivoi , especially given the membranous to weakly coriaceous texture of the leaf blades; however, the pedicels of the former are much thinner and more lax, and its petioles are shorter and much less (if at all) sulcate adaxially. Eugenia diospyroides differs with its generally larger flowers and leaves, and leaves having a rounded apex.

The new species also closely resembles Eugenia radiciflora in leaf morphology, but that species is said to have solitary flowers with pedicels only 2-3 mm long, which does not match the fasciculate brachyblasts of Eugenia ravelonarivoi . The leaves of Eugenia ravelonarivoi also superficially resemble those of Eugenia gandhii , but the latter has densely punctate leaf blades and solitary flowers. Finally, Eugenia ravelonarivoi resembles closely some evidently undescribed taxa

Dr. David Gordon, an entomologist at Pittsburg State University, indicates that the visible damage on the leaves of some specimens may be from leaf cutter bees (Family Megachilidae ), which often damage leaves in this manner to obtain material for the construction of their nests.

Additional specimens.

MADAGASCAR. Prov. Antsiranana: SW d’Andapa, Réserve Spéciale d’Anjanaharibe-Sud, aux enrivons de sommet, 14°46'15"S, 49°28'00"E, 1112-1424 m, 21 Mar.-7 Apr. 1994, Ravelonarivo 103 + F. Rasoavimbahoaka, B.T. Rafaliarimanana, H. Rasitefarinina & Motera (P [P04884879]); Massif de l’Anjanaharibe (pentes et sommet N) a l’W d’Andapa (Haut Andramonta, Bassin de Lokoho), [14°37'S, 49°25'E], 900 m, 10 Dec. 1950-9 Jan. 1951, H. Humbert 24576 + R. Capuron & G. Cours (P [P05208600]); Sud-Ouest d’Andapa, Réserve Spéciale d’Anjanaharibe-Sud, village d’Andranotsarabe, suivant la route Nationale d’Andapa-Bealanana de lat piste vers à l’oueste, Ambatoomainty, Camp No. 2, 14°44'22"S, 49°27'42"E, 3 Nov. 1994, 1185-1335 m, D. Ravelonarivo 489 & R. Babesonina (KSP [KSP003115, KSP003116], P [P05208456]). Prov. Mahajanga: Ankaizinana, [14°30'S, 48°55'E], 1400 m, 20 Apr. 1923, R. Decary 2009 (P [P00118106]).