Eugenia obovatifolia N. Snow

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: 74-75

publication ID

http://dx.doi.org/10.3897/phytokeys.49.9003

persistent identifier

http://treatment.plazi.org/id/FAC9FB04-A492-D5B4-FA3C-A3A7A1552808

treatment provided by

PhytoKeys by Pensoft

scientific name

Eugenia obovatifolia N. Snow
status

sp. nov.

Eugenia obovatifolia N. Snow   sp. nov. holotype (Figure 16): http://www.tropicos.org/Image/100314904

Haec species a congeneris madagascariensibus foliis anguste obovatis atque inflorescentiis glabris saepe ramifloris distinguitur.

Type.

MADAGASCAR. Prov. Toliara: Fokontany: Sainte Luce, 24°46'15"S, 47°10'15"E, 5 m, 5 Nov. 2003, J. Rabenantoandro 1592 + A. Monja (holotype: MO-6038332!; isotypes: P [P04885376]!, TAN).

Description.

Trees 5-14 m; dbh 14-28 cm; bark of main bole unknown. Indumentum (where indicated) of short, ferrugineous, dibrachiate hairs that become increasingly white or grayish. Branchlets rounded laterally compressed, densely short-hairy becoming glabrescent; light brown to light gray (dried). Leaves concentrated near branch tips, coriaceous, surfaces matte. Axillary colleters absent. Petioles 4-8 mm, terete, pubescent when emerging. Leaf blades (3.0-)4.5-6.5 × 1.5-2.5 cm, narrowly obovate (or infrequently ovate); base narrowly cunate; apex obtuse or somewhat acute; margins flat but drying somewhat revolute; adaxial surface glabrous or moderately hairy (especially proximally), oil glands dense (but small; use magnification) on emergence but becoming less visible, midvein slightly sulcate to flush; abaxial surface moderately hairy, oil glands dense but faint; secondary veins 8-15, alternating along midvein, faint; intramarginal vein not visibile. Inflorescences ramiflorous, less than 1.5 cm long, solitary or more commonly fasciculate, of monads, triads, or short botryoids. Pedicels 1-5 mm, stiff, ascending, sparsely hairy to glabrous. Bracteoles 2, ovate, 0.5-1.0 × < 0.5 mm, rigid, sparsely hairy on margins. Hypanthium 2-3 mm, cuplate to obconic, glabrous to densely ferrugineous-hairy, densely glandular (glands relatively large). Calyx lobes 4, 1.5-2 mm, two each relatively large and small, broadly rounded (much broader than long), apex obtuse, sparsely minutely hairy marginally near apex, otherwise glabrous, greenish to cream colored. Petals 5-8 × 5-6 mm, elliptic to ovate, glabrous, whitish to pink or violet, oil glands sparse but easily visible. Stamens ca. 30-50, multiseriate; staminal disk short-hairy, ca. 1.5 mm diameter; filaments 3-5 mm, white; anthers ca. 0.5 mm, globular, basifixed, eglandular, light yellow. Styles 5-7 mm, glabrous; stigma narrow. Berries not seen, but labels indicate pale green (probably immature).

Etymology.

In reference to the shape of the leaf blades.

Vernacular name.

Ropsay (Rabenantoandro 366).

Phenology.

Flowering September, November, and January; fruiting August through December.

Distribution.

East-central Madagascar in Toamasina Province and south-eastern in Toliara Province from Mandena to Sainte Luce (Fig. 11).

Habitat and ecology.

Littoral forest over sand; elevation ca. 5-53 m.

Conservation status.

With an EOO of 8,333 km2, an AOO of 63 km2 and four subpopulations, none of which are situated within the protected network, Eugenia obovatifolia   is assigned a preliminary risk of extinction of “Endangered” [EN 2ab(i, iii, iv)] following the IUCN Red List Categories and Criteria ( IUCN 2012). The new species seems to be restricted to the highly threaten littoral forests and none of the known populations are currently protected.

Comments.

Eugenia obovatifolia   has a general resemblance to Eugenia arenicola   H. Perrier, Eugenia hazompasika   H. Perrier, and Eugenia cloiselii   H. Perrier given its ramiflorous, more or less fasciculate inflorescences. The four species also grow in relative proximity in southeastern and eastern Madagascar, often in sandy littoral forests, and may form a species complex that ranges approximately 1300 km between Taolognaro and Sainte Luce along the coast and somewhat inland to Vatomandry.

Eugenia obovatifolia   differs from Eugenia arenicola   by its more or less glabrous leaves, whereas those of the latter are densely ferrugineous-hairy upon emergence and retain much of the indumentum on the abaxial surface. Eugenia obovatifolia   differs each from Eugenia cloiselii   and Eugenia hazompasika   by virtue of the glabrous (or nearly so) inflorescences, which contrast with the hairy inflorescences of the latter two.

Several indetermined specimens cannot be confidently placed yet given variation in leaf morphology and indumentum (e.g., Razanatsima 31 + Ranaivojaona; Ranaivojaona 1177 + Razanatsima; Razanatsima 711 + Céléstin; Rakotovao 3755 et al. [all at MO]). However, including all of these taxa and specimens into one highly heterogenous species likely would equate to the inappropriate lumping of several independently evolving lineages.

Specimens examined.

MADAGASCAR. Prov. Toamasina: Fokontany: Andravokoditra, 18°34'53"-18°34'20"S, 49°14'42"-49°14'54"E, 7 Jan. 2003, R. Ludovic 228 & F. Rakotoarivony (MO-6038324); Hotel Pangalan on Lake Ampitabe, west of Andranokoditra, 18°35'S, 49°14'E, S.K. Pell 607 + J.D. Mitchell & A. Randrianasolo (MO-5887243); Fokontany: Andranonkoditra Vohibola du côté de l’hôtel Pangalane, 18°35'32"S, 49°14'02"E, 11 Feb. 2003, J. Rabenantoandro 1248 + R. Rabevohitra, P. Lowry, R.Razakamalala & S. Lowry (MO-6038325); Ambinaninony, Andranokoditra, Akinin’ny nofy, 18°34'12"S, 49°14'18"E, 3 Aug. 2003, R. Razakamalala 664 & D. Rabehevitra (MO-6038323); Ambila-Lemaitso, 18°49'S, 49°08'E, 14 Dec. 1967, Service Forestier 28034 (B, BR, G, K, MO-6321087, NY, WAG). Prov. Toliara: Mandena, Jardin Botanique, M16-QMM, Ampasy, Taolagnaro, 24°57'05"S, 47°00'11"E, 26 Sep. 2000, J. Rabenantoandro 241 + P. Lowry, R. Rabevohitra, L. Randrihasipara, & E. Ramisy (MO-5598572); Saint-Luce (Manafiafy), S9, Mahatalaky, Taolagnaro, 24°46'30"S, 47°10'20"E, 16 Dec. 2000, J. Rabenantoandro 366 + F. Lucien & E. Ramisy (MO-5728973); Manambaro, Petriky, 25°03'43"S, 46°52'06"E, 15 Nov. 2006, Ramison 33 (MO-6427490).

Kingdom

Plantae

Phylum

Arthropoda

Class

Insecta

Order

Myrtales

Family

Myrtaceae

Genus

Eugenia