Gossia ouazangouensis N. Snow, 2020

Snow, Neil, 2020, A revision of New Caledonian Gossia N. Snow & Guymer (Myrtaceae), Adansonia 42 (7), pp. 131-177 : 166

Gossia ouazangouensis N. Snow , sp. nov. ( Figs 17 ; 18F-I )

The species can be distinguished by its thin whitish calyx lobes, glabrous hypanthium, and a mostly terminal to subterminal infloresence that significantly exceeds the length of the leaves. It somewhat resembles Gossia kaalaensis sp. nov., but the adaxial leaf surface of the latter is glossy and has prominently raised secondary veins and an acute apex, and thicker and greenish calyx lobes. In contrast, the adaxial leaf surface of G. ouazangouensis sp. nov. is matte with flush secondary veins and an obtuse apex and thin, whitish or whitish-green calyx lobes. TYPUS. — New Caledonia. Grande Terre, North Prov ., pente Ouest de Mt Ouazangou, 20°44’47.00”S, 164°27’56.16”E, 19.VI.1967, MacKee 16927 (holo-, P [ P00751831 ]; iso-, BISH[fragment], NOU[NOU030913]).

PARATYPI. — New Caledonia. Grande Terre. North Prov. , Poum, 30 m, 27.IV.2004, G. Dagostini 843 & Nigote ( NOU, P[P05121896, P05121897], WELTU n.v.) ; Mont Ouazangou Pente Ouest , 20°44’47.00”S, 164°27’56.16”E, 300-500 m, 4.III.1972, MacKee 25123 ( NOU [ NOU029637 ], P[P02089986] with dups [n.v.] to distribute to BISH, CHR, G, MO, NSW, RB, TNS]) ; Kaala-Gomen , Massif Onajiele, 20°46’07.02”S, 164°27’44.65”E, c. 100 m, 16.V.2015, Munzinger 7592 (leg. Scoptera) ( MPU [ MPU620439 ]). — South Prov., Vallée de la Tontouta, 21°56’36.99”S, 166°17’35.99”E, 0-50 m, 22.III.2006, Pillon 329 et al. ( NOU [ NOU011598 ], P[P06668689]). REPRESENTATIVE HERBARIUM SPECIMEN. — P00751831 .

ETYMOLOGY. — From the type locality.

DISTRIBUTION, HABITAT AND PHENOLOGY. — Known from the western peak of Mont Ouazangou (Massif Onajile) and Poum in the northwest, and Tontouta in the southwest ( Fig. 17 ); in maquis on ultramafics from near sea level to 500 m. Flowering approximately April through June; fruiting unknown.

DESCRIPTION

Tree-like shrubs

To 2- 5 m.

Bark Light reddish or grayish and craking longitudinally.

Branchlets Terete; internodes> 5 mm.

Leaves

Coriaceous, 2 per node; petioles 1.5-3 mm, sulcate; blades (2.5-)6.0-7.5 × 1.2-3.3 cm, ovate, base cuneate, surface flat, margin slightly revolute throughout, apex obtuse, midnerve sulcate in lower half, secondary veins mostly flush above, oil glands of lower surface common but faint.

Inflorescence

1.5-4.5 cm, mostly of 3-flowered cymes (infrequently of monads), axillary or terminal; extrafloral bracts absent or scale-like.

Bracteoles 0.9-1.2 mm, linear to narrowly elliptic, sparsely sericeous.

Hypanthium 2-3 × 2-3.5 mm, obconic, surface smooth, glabrous.

Calyx

Lobes 5, 1.1-2.8 mm, broadly rounded, glabrous above but ciliate on margins, glabrous below, drying whitish.

Petals

6.0-6.5 × 5-6 mm, glabrous above but ciliate on margins, glabrous below, whitish.

Filaments

4-5 mm, pinkish to the base; anther sacs c. 0.5 mm.

Style

5-6 mm, sparsely villous, especially in lower half; ovary apex hairy at base of style.

Fruits

Unknown.

REMARKS

The inflorescence branches on MacKee 25123 are somewhat shorter and more gracile, and the branches more reddish and with a flakier epidermis, but the leaf morphology, locality and substrate of the two collections otherwise match well. An uplaced 4-merous specimen (Munzinger 7890 [MPU640674; P020290978]) may be this species.

Figures

FIG. 17. — Distribution maps of G. kaalaensis N. Snow, sp. nov., G. mandjeliaensis N. Snow, G. nigripes (Gullaumin) N. Snow, and G. ouazangouensis N. Snow, sp. nov.

FIG. 18. — A-C, Gossia ngaensis N. Snow, sp. nov.: A, adaxial surface of leaf (right) with detail (left) venation; B, tip of branch with solitary young fruit; C, seed (left) and fruit (right). D, E, Gossia nigripes (Guillaumin) N. Snow: D, branch with fruits; E, detail of leaf (with dark petioles) and fruit; F-I, Gossia ouazangouensis N. Snow, sp. nov.: F, flowering branch with abaxial oil gland details (lower left); G, branchlet showing cracking epidermal layer; H, detail of cyme; I, detail of flower prior to anthesis. Vouchers: A-C, McPherson 4878 (NOU); D-E, McPherson 4509 (WELTU); F-I, MacKee 16927 (P). Scale bars: A, B, D, 2 cm; C, E, F-I, 5 mm.