Eugenia tiampoka 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 : 83-85

Eugenia tiampoka N. Snow & Callm. sp. nov. holotype (Figure 20): http://www.tropicos.org/Image/100314918; Living material: http://www.tropicos.org/Image/76837

Haec species Eugeniae thouvenotianae H. Perrier simillima, sed ab ea lamina foliari glandulis oleiferis punctatis abaxialiter ornata atque pedicellis multo brevioribus distinguitur.

Type.

MADAGASCAR. Prov. Antsiranana: Doany, en aval des deux côtes de la rivière Ambalanirano. Ambohimirahavavy, 14°13'43"S, 49°08'07"E, 2011 m, 19 Nov. 1995, C. Rakotovao 2511 + Jaovazaha & Tsarajery (holotype: MO-6174870!; isotypes: G [G00341423]!, P [P05260190]!, TAN).

Description.

Trees 8-18 m; dbh 12-60 cm; bark of main bole unknown. Indumentum of foliage and floral parts dibrachiate, short and appressed, ferrugineous, denser upon emergence but becoming (often) nearly glabrous (or as indicated below). Branchlets rounded to laterally compressed, greenish fresh but drying light brown to light gray; epidermis thin and peeling away in thin strips or flakes, oil glands absent to sparse and indistinct. Leaves discolorous, margin sometimes strongly revolute and irregularly sinuous, venation reticulate, emerald and somewhat glossy adaxially, citrine and matte abaxially, concentrated near branch tips. Axillary colleters occasionally present. Petioles (2.5-)5-10, narrowly and deeply sulcate adaxially, elgandular. Leaf blades 4.0-6.8 × 2.3-.8 cm, elliptic to obovate, base cuneate, apex obtuse or occasionally retuse; adaxial surface remaining at least sparsely sericeous when fully emerged (trichomes closely appressed), oil glands common to dense but faintly visible, midvein deeply and narrowly suclate proximally becoming flush distally; abaxial surface indumentum as above, oil glands not as dense but much more prominent, secondary veins indistinct to somewhat prominent, intramarginal vein 1.0-1.5 mm from margin at midpoint of leaf blade (but often obscured by revolute margin). Inflorescence 2-5 cm long, mostly axillary or ramiflorous, sometimes terminal, consisting of triads, botryoids, or less commonly metabotryoids or pseudo-umbels of 4-5 flowers apically clustered on peduncle; peduncles mostly solitary but often opposite in leaf axils or on naked branches, mostly ascending and somewhat stiff but also sometimes flexuous. Pedicels 1-2 mm long. Bracteoles absent; bract-like structures surrounding triads of flowers when inflorescence is emerging but these soon deciduous. Hypanthium 1.5-2.5 mm, obconic, densely hairy and densely punctate. Calyx lobes 4, (1.2-)1.5-1.8 mm, broadly rounded, apex obtuse, mostly glabrous above to sparsely sericeous, moderately sericeous dorsally and on margins below, deciduous in fruit, light green when fresh. Petals 4, 4-7 mm, obovate, minutely and sparsely ciliate apically (use magnification) but otherwise glabrous, oil glands sparse to moderate. Stamens 20-45, exserted; staminal disk glabrescent; ovary apex glabrous; filaments 4-7 mm, yellowish-white; anthers 0.4-0.6 mm, globose to subelliptic, basifixed, eglandular; style 4-5 mm, stigma narrow and scarcely if at all capitate. Fruit (material limited), ca. 2.2 × 2.2 cm, globose, glabrate, green when young drying nearly black; outer layer leathery and prominently glandular. Seed 1 at maturity (material scant), round from above but laterally compressed (due to pressing?), ca. 16 × 16 × 9 mm; embryo not differentiated into distinct cotyledons or epicotyl.

Etymology.

The specific epithet is derived from elements of the native language of northern Madagascar, in which ampoka means mosses. Eugenia tiampoka thus means the " Eugenia that likes mosses".

Phenology.

Flowering October through February; fruiting by early April, likely commencing by March and extending through May.

Distribution.

Northern Madagascar in Antsiranana Province in the northern mountains (Fig. 2).

Habitat and ecology.

Mid- to high-altitude humid forests laden with mosses, sometimes along river banks; 1990-2300 m in the northern highlands of Madagascar. A team of botanists lead by MC conducted a series of field expeditions between 2005 and 2008 to explore the flora and vegetation of this long-neglected region, during which more than 4,400 collections were made, yielding material of several plant species new to science ( Callmander et al. 2008, 2009, 2012).

Conservation status.

With an EOO of 71 km2, an AOO of 45 km2 and two subpopulations, neither of which is within the protected area network, Eugenia tiampoka is assigned a preliminary risk of extinction of “Endangered” [EN B1ab(iii)+2ab(iii)] following the IUCN Red List Categories and Criteria ( IUCN 2012).

Comments.

The leaves reportedly are aromatic (Birkinshaw 950, Rakotovao 2398). One specimen is said to have a nectariferous disk (Randriarivelo 350). A specimen of 30 m stature (Ravelonarivo 647) from the same general area and also said to be aromatic, but growing at 1700 m, has a slightly different aspect to the leaves, also may be this species.

The morphological gestalt of the leaves and inflorescences resemble most closely those of Eugenia thouvetiana H. Perrier, which however lacks the punctate oil glands of the abaxial leaf surface, and which has much longer pedicels subtending the individual flowers than those of Eugenia tiampoka . The type locality of Eugenia thouvetiana is located in Analamazaotra-Andasibe in Toamasina Province, some 525 km south of the southernmost known collection of Eugenia tiampoka . Eugenia tiampoka also somewhat resembles Eugenia hazompasika H. Perrier, the latter of which has much longer, broader and stiffer leaves with a less abruptly cuneate base.

Specimens examined.

MADAGASCAR. Prov. Antsiranana: 13 km N of Mangindrano, Tsaratanana Massif, SW ridge of Andomanisambiraro, 14°08'41"S, 48°57'53"E, 2150 m, 17 Oct. 2001, C. Birkinshaw 950 + R. Lala (KSP [KSP000048, KSP000049], P [P05156041]); Crête E d’Ambohimirahavavy, 14°12'15"S, 49°05'54"E, 2278 m, 3 Nov. 2005, C. Rakotovao 2398 + Jaovazaha & Torize (G, MO-6202095); Sommet de Beampoko, Ambohimirahavavy, 14°13'55"S, 49°08'23"E, 2137 m, 21 Nov. 2005, C. Rakotovao 2566 + Jaovazaha & Tsarajery (G, MO-6174671, P [P05260203]); Doany, forêt d’altitude d’Ambohimirahavavy, 14°13'41"S 49°08'14"E, 1991 m, 18 Nov. 2005, C. Randrianarivelo 350 + J. Randriantiavina & Torize (G, MO-6081166), KSP [KSP000047], P [P05260189]); Fokontany: Ampanompy, Ampanompy, 14°08'31"S, 48°58'04"E, 2050-2300 m, 5 Apr. 2001, R. Razakamalala 99 + R. Ranaivojaona, F. Ratovoson, A. Rasolohery, A. Andriamaniry & Mahavory (KSP [KSP000047]!).