Eugenia guajavoides N. Snow & F. Randria., 2012

Snow, Neil, Rabenantoandro, Johny, Randriatafika, Faly, Rabehevitra, David, Razafimamonjy, N. Darie & Cable, Stuart, 2012, Studies of Malagasy Eugenia (Myrtaceae) - III: Seven new species of high conservation concern from the eastern littoral forests, Phytotaxa 48 (1), pp. 39-60 : 42-44

Eugenia guajavoides N. Snow & F. Randria. , sp. nov. ( Figs. 2 , 3 ).

A congeneribis madagascariensibus combinatione characterum sequentium distinguitur: arbores usque ad 8 m altae; pedicelli magentei crassi; hypanthium et calycis lobi flavovirentes; petala subrosea; filamenta et styli albidi; antherae eburneae.

Type: ― MADAGASCAR. Prov. Toliara: Region of Tolagnaro; on QIT concession, Mandena site; 24°57’S, 47°00’E, 25 m, 17 October 1989, G. McPherson 14145, N. Dumetz, & R. Rabevohitra (holotype MO! [sheet no. 3771530]; isotypes BISH! [2 sheets, nos. 747509 and 747510], P) .

Trees 2–8 meters. Indumentum (where present) moderately to densely short-sericeous; trichomes dibrachiate, whitish-brown. Branchlets laterally compressed, emerald green when young becoming brownish (grayish dried), smooth, densely short sericeous on emergence but becoming glabrous; oil glands absent; internodes 1– 3 cm long. Leaves thickly coriaceous, evenly distributed along branchlets, emerald green and glossy above, matte and lighter green below (strongly discolorous and brown when dry); venation brochidodromous. Stipules absent. Petioles 5–10 mm, slightly sulcate above, emerging sericeous but becoming glabrous, eglandular, rugose-wrinkled. Leaf blades 4.4–9.0 x (2.0–)3.0– 4.5 cm, elliptic to obovate and often slightly falcate, base cuneate, apex obtuse and sometimes slightly asymmetrically conduplicate at tip, margin drying slightly revolute, blade flat to slightly bullate between secondary veins; adaxial surface emerging sericeous but becoming glabrous, oil glands absent, midvein mostly flush or slightly sulcate proximally; abaxial surface glabrous, oil glands absent, secondary veins indistinct, not or only slightly looping at connection to intramarginal vein, intramarginal vein faint, 1–2 mm from margin at laminar midpoint. Inflorescence only partially known, evidently a few-flowered cyme, ramiflorous, solitary or paired (possibly fascicled but not confirmed), pedicels stiff, 8–9 mm long, terete, sericeous, often pink, oil glands absent. Bracteoles 1.0– 1.2 mm long, ca. 0.8 mm wide, broadly ovate, stiff, sparsely sericeous below, often persisting in fruit. Calyx lobes 4, 3.0– 4.5 mm long, rounded, apex obtuse, sericeous above, sericeous below (especially proximally). Petals 4, pinkish throughout or nearly white on margins. Stamens numerous (100+, estimated), filaments whitish, anther sacs globose, cream or ivory-colored. Style white. Fruit 12–17 mm long, 12–18 mm wide, globose, base rounded, sericeous, greenish-brown to maroon, crowned by persistent calyx lobes. Seeds globular to subglobular, 1 per fruit, 9–12 mm long, whitish (fresh) drying nearly black, partially encircled by flattened, belt-like hypocotyl (see e.g., Snow 2011, Fig. 6e ).

Field characters:— Trees 2 to 8 meters tall. Leaf blades emerald green and glossy above, slightly asymmetrical to falcate, the apex sometimes slightly (and asymmetrically) conduplicate. Petals white or pinkish; filaments and styles whitish, anthers ivory to tawny.

Distribution:— Eugenia guajavoides occurs in southeastern Madagascar about 10 km northeast of Tolagnaro. The eastern collection (paratype) is in or very near the conservation parcel M3 of Mandena Forest. It is uncertain whether the western collection (type gathering) is in, or only adjacent to, the conservation zone M16 of Mandena Forest ( Fig. 2 ; see also Lowry et al. 2008).

Habitat and ecology: Littoral forest.

Phenology:— Flowering confirmed only for late December but assuredly occurring well into January.

Fruiting confirmed for October but probably beginning much earlier.

Additional specimen examined (paratype):— MADAGASCAR. Prov. Toliara: Mandromodromotra, Parcelle M 2, Fokontany Lokaro, Firaisana Mandromodromata, Fort-Dauphin, 24°57’44”, 47°03’56”E, 3 October 2000, R. Rabevohitra 3727 et al. (MO) .

Etymology:— Derived from the specific epithet of the common guava, Psidium guajava L. given the similarities of the fruits. The local vernacular name, sarigoavy, indicates that it resembles a guava fruit.

Conservation status:— Eugenia guajavoides is known from a single subpopulation. The relatively imprecise coordinates of the type specimen were added after the collection was made (Z. Rogers, pers. comm. 2010) so it is uncertain whether it and the paratype gathering occur within a Protected Area ( Fig. 2 ). With an AOO of 18 km 2, one subpopulation, only two collections from a relatively well-collected region, and an estimated number of individuals of less than 250, Eugenia guajavoides is assigned a prelminary status of “Endangered” (EN: D).

Discussion:— Flowers are unknown from herbarium material; measurements and information were taken from fruiting material and digital images.

Figures

FIGURE 2. Distribution of species and selected specimens of Eugenia in southeastern Madagascar based on vouchered herbarium specimens and recently captured (but non-vouchered) digital images. Remaining forested areas (Petriky, Mandena, Sainte-Luce) along the coast are indicated in gray. In cases where the icons largely or completely overlapped based on geo-coordinates they have been separated slightly for easier viewing (e.g., E. ardyceae, E. stictophylla and E. cloiselii along the coast west of Tolagnaro). Many additional specimens of Eugenia from the region await identification or description and cannot be mapped confidently at the present time.

FIGURE 3. Eugenia guajavoides. (No voucher; photo by J. Rabenantoandro).

FIGURE 6. Isotype of Eugenia stictophylla (Dumetz 1106 & McPherson [BISH]).