Eugenia homedeboana N. Snow

Neil Snow, John W. Dawson, Martin W. Callmander, Kanchi Gandhi & Jérôme Munzinge, 2016, New Species, New Combinations, and Lectotypifications in New Caledonian Eugenia L. (Myrtaceae), Candollea 71 (1), pp. 67-81 : 70

Eugenia homedeboana N. Snow , spec. nova

( Fig. 1 , 3 ).

Typus: New CaledoNia. Prov. Nord: Taom , Mt Homedeboa , 800-900 m, 16.X.1969, MacKee 20983 (holo-: P [ P06138878 ]!).

Distinct among congenerics in New Caledonia by the brownish velutinous abaxial leaf surface that turns grayish as the leaf matures, and its sessile clasping ovate leaves.

Shrubs to 1 m. Bark smooth or slightly rough, greyish. Branchlets laterally compressed, reddish-brown (when young) by virtue of short but dense velutinous indumentum. Leaves sessile, stiffly coriaceous, venation brochidodromous, discolorous, surfaces matte, evenly distributed along branchlets. Foliar colleters not seen. Leaf blades 3.5- 8 X 2.5-5 cm, ovate, bases cordate and strongly clasping, apex obtuse, margins somewhat irregularly revolute; adaxial surface appearing glabrous but on close inspection (use high magnification) with moderately dense indumentum of minute, irregularly twisting to somewhat glandular grayish trichomes, midvein flush or slightly and narrowly raised proximally, secondary veins faint, intramarginal vein not visible; abaxial surface like upper surface but indumentum much denser and trichomes dark reddish-brownish when young and becoming grayish, secondary and marginal veins obscured entirely by indumentum. Inflorescences of solitary monads, these ramiflorous towards base of branchlets and axillary. Peduncles rigid, 6-7 mm, densely velutinous. Bracteoles ca. 1.5 X 1 mm, triangular but obscure (erect and appressed against hypanthium), rigid. Hypanthium cupuliform, ca. 7 mm long, densely velutinous, pinkish in bud. Calyx lobes 4, distinct in bud, 2.5- 3 X 2-6 mm (sometimes much broader than long), broadly rounded to triangular, apex rounded to acute, velutinous abaxially, less so adaxially. Petals 4, 7- 9 X 6-8 mm, very widely ovate to oblate, ciliate on margins, white, oil glands faint. Stamens numerous (> 100), multiseriate; filaments up to 4 mm long, anthers 0.7-1.0 mm, ellipsoid, basifixed, eglandular. Ovary apex densely short-hairy surrounding base of style.

Style (material scant) ca. 5 mm, glabrous; stigma narrow and barely capitate. Fruits 17- 20 X 14-18 mm (material limited), asymmetrically sub-ellipsoid (the crowning calyx lobes offset ca. 45° from axis of petiole), based rounded or tapered and somewhat asymmetrically attached, brown-velutinous.

Distribution, ecology and phenology. ‒ Known only from the northwest on ultramafics and maquis ( Fig. 2 ). Flowering in October and likely into December, fruiting in December.

Conservation status. ‒ The Tsiba locality (MacKee 34497) is included in an ancient mining concession, and the vegetation was mainly cleared in that area, while Mt Homedeboa, the type locality, was severely damaged by fires. Thus, the new species is facing serious threat and with only two locations and an AOO of 8 km 2, E. homedeboana is assigned a preliminary IUCN conservation status of “Endangered” [EN B1ab(ii,iii,v)+2ab(ii,iii,v)].

Notes. ‒ The leaf morphology of E. homedeboana closely resembles that of E. virotii Guillaumin , but differs its dense abaxial indumentum. It also resembles E. kaalaensis Guillaumin , which has an identical indumentum of the leaves, but that species is distinctly petiolate.

The type specimen is in flower (although the collection label says the fruits are brown), that of MacKee 34497 is in bud, and Vieillard 2593 bears two fruits.

Paratypi. ‒ New CaledoNia. Prov. Nord: Gatope , Vieillard 2593 ( P [ P04722710 ]); Ouaco, Tsiba , 400 m, 31.XII.1977, MacKee 34497 ( NOU [ NOU 031553 ], P).

Figures

Fig. 1. – Distribution of new species of Eugenia L. in New Caledonia mapped on ultrabasic rocks (light grey) and protected areas (dotted stippling): E. amosensis N. Snow (circle), E. homedeboana N. Snow (squares), E. sicifolia J. W. Dawson & N. Snow (pentagons), E. tchambaensis J. W. Dawson & N. Snow (stars), and E. tiwakaensis J. W. Dawson & N. Snow (crosses).

Fig. 2. – Holotype of Eugenia amosensis N. Snow. [Munzinger et al. 1488, P] [© Muséum national d’Histoire naturelle, Paris. Reproduced with permission]

Fig. 3. – Holotype of Eugenia homedeboana N. Snow. [MacKee 20983, P] [© Muséum national d’Histoire naturelle, Paris. Reproduced with permission]