Eugenia ranomafana N. Snow & D. Turk, 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 : 76-77

Eugenia ranomafana N. Snow & D. Turk sp. nov. holotype (Figure 17): http://www.tropicos.org/Image/100314914

Haec species a congeneris madagascariensibus ramulis in sectione transversali non profunde sed late sulcatis, foliis saepe 3- vel 4-verticillatis atque hypanthio sub anthesi discoideo distinguitur.

Type.

MADAGASCAR. Prov. Fianarantsoa: Ranomafana PN, Ifanadiana, à 60 km au Nort-Est de la ville de Fianarantsoa, le long de la piste Cabine de Recherche, Vatoaranana, 10 Oct. 1996, 21°13'37"S, 47°22'11"E, 1500-1600 m, R. Randrianaivo 12 et al. (holotype: MO-6224857!; isotypes: KSP [KSP000044, KSP000045]!; P [P04885335]!, TAN).

Description.

Shrubs or trees, 3-8 m tall; dbh 2.8 cm; bark of main bole unknown. Foliage and flowers glabrous except as noted below. Branchlets laterally compressed to terete but sometimes trigonal in cross section, and irregularly and broadly and prominently sulcate on one or more sides, flaring distally below nodes but becoming rounded; smooth but sometimes striate, sparsely serciceous (trichomes reddish and dibrachiate) but soon glabrous, epidermis reddish or maroon on emergence but becoming irregularly and finely brown-gray mottled (dried material). Leaves opposite to disjunct opposite or whorled in 3s or 4s, concentrated near branch tips; coriaceous; venation brochidodromous; surfaces concolorous, matte; lateral veins 20-32 on each side, arising at an angle of 65-75˚ from the midrib. Axillary colleters lacking. Petioles 3-7(-12) mm, deeply sulcate adaxially, prominently striate-rugose (especially abaxially), eglandular. Leaf blades (4.4-)6.0-16.0 × (1.9)2.8-3.3 cm, narrowly elliptic, often conduplicate (dried material) in lower ca. 20%, base mostly rounded (sometimes cuneate), apex obtuse but sometimes slightly falcate, margin and surface somewhat sinuous; adaxial midvein deeply sulcate throughout, eglandular; abaxial surface eglandular except on midvein (glands moderately dense and somewhat indistinct); secondary veins consisting of (16-)25-32 pairs, indistinct but slightly raised, diverging at wide angle from midvein; intramarginal vein indistinct, 1.5-2.5 mm from margin of leaf at midpoint of blade. Inflorescence of solitary, paired, or fasciculate and ramiflorous monads. Pedicels (4.5-)8-17 mm, stiff but thin, terete to slightly compressed. Bracteoles 2, 0.5-0.7 × ca. 0.2-0.5 mm, broadly ovate, apex rounded, horizontal to reflexed in fruit, occasionally a few short trichomes. Hypanthium 0.5-1.5 mm long; initially cupuliform but becoming discoid (prominently flattened from above) during and after anthesis, glabrous, oil glands common, cream-colored (fresh). Calyx lobes 4 (but of unequal lengths), the two shorter lobes broader than long, ca. 1.5 × 2.2 mm broad at base, the two longer lobes hemispherical, ca. 2 × 2 mm, glandular, pale green (fresh), persisting or deciduous in fruit, ascending or crowing mature fruit. Petals 4, ca. 4 mm × 3.2 mm, broadly obovate to broadly elliptical, pink, with 9 veins arising from the base. Staminal disk diameter (in fruit) 3.5-5.0 mm; glabrous. Stamens ca. 60-80; filaments (1.5-)4-6 mm, cream-colored; anther sacs ca. 0.5 mm, subglobose to globose, connective apex eglandular; staminal disk glabrous. Style ca. 4-6 mm; stigma narrow. Fruit 11-18 × 8-23 mm, subglobose with irregular lobes (but not costate), base rounded, green (young fresh) but drying dark bluish-black, locules 2, placenta capitate, placentation axile, ovules radiating from center of placenta. Seeds 3-4 per fruit; outer coat leathery, highly contorted, drying to a light yellowish-brown ( “fawn”) or dull brownish-yellow ( “tawny”, Beentje 2010).

Etymology.

From Ranomafana National Park.

Phenology.

Fruiting October and November; flowering May.

Distribution.

Known from three collections in Ranomafana National Park in Fianarantsoa Province, southeast-central Madagascar (Fig. 4).

Habitat and ecology.

Growing in the undergrowth or subcanopy in humid forests, ca. 950-1600 m. The collection by Turk notes its occurrence with trees of the genera Weinmannia L., Tambourissa Sonn., Decarydendron Danguy, Ephippiandra Decne., Ocotea Aubl. and Cryptocarya R. Br., and understory with Psychotria L. and Oncostemum A. Juss.

Conservation status.

With only three collections known, an AOO of 9 km2 and one subpopulation, which is situated within the protected area network (Ranomafana), Eugenia ranomafana is assigned a preliminary risk of extinction of “Vulnerable” [VU D2] following the IUCN Red List Categories and Criteria ( IUCN 2012).

Comments.

This species was first recognized as undescribed by Turk (1997) as part of a dissertation studying plants in Ranomafana National Park, who approved of and collaborated with its publication here.

With its narrowly elliptic leaf blades with mostly rounded leaf bases, Eugenia ranomafana resembles mostly closely Eugenia wilsoniana , the nearest occurrence of which is ca. 280 km northeast. Eugenia wilsoniana differs by its shorter stature, leaf margins being flat to only slightly sinuous, longer and thinner (on average) pedicels, presence of axillary colleters, and a hairy staminal disk. In addition, Eugenia ranomafana differs by its often trigonous branchlets and the frequent occurrence of 3-4 leaves per node.

Specimens examined.

MADAGASCAR. Prov. Fianarantsoa: Ranomafana National Park, parcelle 3, S of National Road 25 at 7 km W of Ranomafana; Talatakely trail system, 21°15'30"S, 47°25'00"E, 950-1150 m, 4 May 1993, D. Turk 436 + J. Randrianasolo, J. Solo, & D. Randriamanatenta (MO, KSP); Ranomafana National Park, Talatakely parcel, Trail System F-TBT-B, 21°15'S, 47°25'E, P. Fritsch 1643 et al. (CAS, MO-6287616).