Eugenia stictophylla N. Snow & Razafim., 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 : 49-51

Eugenia stictophylla N. Snow & Razafim. , sp. nov. ( Figs. 2 , 6 ).

A congeneribis madagascariensibus combinatione characterum sequentium distinguitur: arbor 4–7 m alta; petioli 3.5- 5.5 mm longi, sulcati; folia 20–50 mm longa, 7–12(–15) mm lata, anguste elliptica, basi cuneata, apice obtuso, lamina dense glandulosa; petala alba; stamina 35–70.

Type: ― MADAGASCAR. Prov. Toliara: District Tolagnaro ; forêt de Petriky. 25°05’S, 46°52’E, 5 December 1990, N. Dumetz 1106 & G. McPherson (holotype MO! [sheet no. 3778655]; isotypes BISH! [sheet no. 747508], MO, P, TAN) .

Trees 4–7 meters. Indumentum (where present) shortly sericeous, trichomes dibrachiate and ferrugineous. Branchlets laterally compressed and maroon or pinkish on emergence, becoming terete and grayish (dried), smooth, sericeous below the base of (often supra-axillary) pedicels but glabrous or only sparsely sericeous elsewhere; oil glands sparse, indistinct; internodes 1.0– 2.2 cm long. Stipules of short, setose hairs (type A: Snow et al. 2003:7). Leaves thinly coriaceous, mostly evenly spaced on branchlets, secondary veins faintly protruding above (dried material), slightly discolorous, somewhat glossy above, matte below; venation (obscurely) brochidodromous. Petioles 3.5–5.5 mm long, deeply sulcate adaxially, prominently glabrescent along apex of sulcus, abaxially verrucose. Leaf blades 2.0–5.0 x 0.7–1.2(–1.5) cm, narrowly elliptic, base strongly cuneate, margin flat or drying slightly revolute, obtuse; adaxial surface glabrescent, secondary nerves indistinct and somewhat protruding (dried material), oil glands small but dense (use magnification), midvein sulcate proximally but becoming flush distally; abaxial surface glabrous, oil glands much less prominent than above, secondary veins obscure (sometimes scarcely visible), of 10–14 pairs, intramarginal vein indistinct, closely paralleling margin, ca. 0.5 mm from margin at midpoint of blade. Inflorescence a solitary flower, axillary or (mostly) supra-axillary. Peduncles 7–12(–15) mm long, laterally compressed (dried), mostly ascending, somewhat flexuous, sericeous near base but more sparsely distally, oil glands faint, moderately common. Bracteoles 2, 0.5–1.0 mm long x <0.5 mm, ovate to broadly ovate, scale-like, stiffly erect to ascending, stiff, sparsely sericeous, persisting in flower. Hypanthium 1.5–2.0 mm long (dried), ca. 1.3–2.4 mm wide below base of calyx lobes, obconic, terete, sparsely sericeous (especially above base of bracteoles towards calyx lobes), oil glands small but dense. Ovary apex sparsely short-villous along outer edges (i.e., in region adjacent to inner margin of staminal ring). Calyx lobes 4, 1.5–3.0 mm long, distinct and dimorphic in bud (the inner 2 somewhat longer than the outer 2), orbicular to shortly to broadly ovate, ciliate and sparsely sericeous, densely glandular (glands larger and more protruding than those of hypanthium), persistence in fruit unknown. Petals 4, 5– 7 mm long, (2.5–)3.5–4.0 mm wide, obovate or widely obovate, white, glabrous, oil glands common and of similar size to those of calyx lobes. Stamens 35–70, in several whorls; filaments 3–6 mm long; anthers 0.5–0.8 mm long, globose to subcylindrical, sub-basifixed, with a single prominent apical gland. Style 4.5–5 mm long, glabrous, tapering to a narrow punctiform stigma. Locules 2; placentation parietal, placenta capitate from middle of locule; ovules 8–13 per ovary, radiating from placenta. Fruit ca. 2–3 x 2–3 cm, yellowish-brown.

Field characters: ―Trees 4–7 meters. Petioles deeply sulcate above; leaves densely glandular on upper surface, narrowly elliptic, apically obtuse. Petals white.

Distribution: ―Known only from Petriky and Ambinanibe forests west of Tolagnaro.

Habitat and ecology: ―Littoral forests on sand; elevation to about 15 m.

Phenology: ―Flowering December and January; fruits not known.

Etymology: ―The specific epithet is derived from the Greek elements stict and phyll in reference to the densely glandular leaves.

Additional specimen examined (paratype): ― MADAGASCAR. Prov. Toliara: Tolagnaro region; SW of town in forest called Petriky , along QIT road, 25°05’S, 46°52’E, 12 January 1990, G. McPherson 14774 et al. (G, K!, MO!, P, TAN) .

Conservation status: ―The imprecise geo-coordinates preclude knowing whether the two specimens occur(ed) in conservation zone P1 of Petriky Forest ( Fig. 2 ; see also Lowry et al. 2008). With just two collections from a restricted forest, an AOO of 9 km 2, and a single subpopulation constituting a single location with an estimated number of less than 250 individuals, near or within a protected area (Petriky), E. stictophylla is assigned a preliminary status of “Endangered” (EN: D).

Discussion: ―Our reports of fruiting material are taken from the field and from information provided by people locally who know the species. Among other species of Eugenia in the vicinity of Petriky Forest, Eugenia stictophylla most closely resembles Eugenia cassinoides Lam. However , E. stictophylla has a more deeply sulcate petiole, more narrowly elliptic leaf blades, denser and much darker laminar oil glands (living and dried material), and more flexible pedicles. The leaf blades of the new species tend to dry significantly greener than those of E. cassinoides , the latter of which typically dry darkish brown adaxially, although the dried color may be an artifact of drying temperatures and duration.

The paratype specimen of E. stictophylla may be slightly introgressed with the much more common E. cassinoides , although genetic studies would be necessary to test this hypothesis. Differences of the paratype from the type gathering include fewer stamens (ca. 35–45 v. 60–70), subglobular ( v. cylindrical ) anther sacs, and fewer (8–9 v. 11–13) ovules per locule.

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