Gossia katepahiensis N. Snow, 2020

Snow, Neil, 2020, A revision of New Caledonian Gossia N. Snow & Guymer (Myrtaceae), Adansonia 42 (7), pp. 131-177 : 160

Gossia katepahiensis N. Snow , sp. nov. ( Figs 14 ; 15A-C )

Resembling Gossia kuakuensis but differing by its narrower bracteoles; similar to Gossia vieillardii but having rounded leaf bases; and differing from Gossia bourailensis sp. nov. by the broadly obtuse to rounded apex of the leaf.

TYPUS. — New Caledonia. Grande Terre , North Prov. , Mt. Katépahié, above Voh, 20°55’58.08”S, 164°41’33.00”E, 4.V.1983, c. 350 m, McPherson 5690 (holo-, P [ P00402743 ]; iso-, BISH [fragment], BRI, MO[ MO-3183836 ], NOU [ NOU030911 ], NSW, WELTU [2 sheets]).

PARATYPI. — New Caledonia. North Prov. , Voh, Massif Katépahï, en haut d’un sentier de randonnée, 20°55’26.36”S, 164°42’16.94”E, c. 530 m, 19.IX.2016, Munzinger 7867 (leg. Scoptera) ( MPU [ MPU640688 ]; P[P02090939]) .

REPRESENTATIVE HERBARIUM SPECIMEN. — P00402743. ETYMOLOGY. — Derived from the type locality.

DISTRIBUTION, HABITAT AND PHENOLOGY. — Known from two collections on Mt. Katépahie ( Fig. 14 ) from forest remnants over ultramafics from approximately 350-530 meters. Flowering in May; fruiting in August.

DESCRIPTION

Rounded shrubs to trees

1.5- 3 m.

Bark Light gray to almost white and longitudinally furrowed.

Branchlets Terete, bright red on emergence; internodes> 5 mm.

Leaves

Coriaceous, 2 per node; petioles 2.5-4 mm, sometimes slightly sulcate; blades 2.2-5.5 × 1.5-3.5 cm, elliptic, base rounded, surface flat, margin slightly recurved and surface slightly undulate, apex rounded to broadly obtuse (and sometimes slightly retuse), midnerve sulcate above, secondary veins faintly visible above and below, oil glands of lower surface faint and moderately common.

Inflorescence

Of monads or elongated racemes, axillary and terminal; extrafloral bracts absent or scale-like.

Bracteoles

1-2 mm, narrowly obovate, glabrous.

Hypanthium

2.5-3 × 2-3 mm, obconic, surface smooth, glabrous to sparsely sericeous; ovary apex glabrous.

Calyx

Lobes 5, 1- 1.5 mm, broadly rounded, sparsely sericeous near base above, glabrous to sparsely sericeous below, green.

Petals 4-5 × 3-4 mm, ciliate on margins, glabrous below.

Filaments 3-5 mm; anther sacs 0.4-0.6 mm.

Style

c. 5 mm, sericeous.

Fruits (young)

7-8 mm, ellipsoid and somewhat tapered at the base, light green but beginning to darken; seeds up to 2.

REMARKS

This species resembles several others in Gossia . Its leaf apex is rounded to broadly obtuse (and sometimes slightly retuse), and the secondary veins are visible in sicco. Mature inflorescences typically are longer than the adjacent leaves, and the inflorescence and pedicels are relatively thin and often somewhat bowed. In addition, the base of the petals is thicker than most other species.

A specimen I annotated in 2004 with this name (P[P00402742]) likely represents a different taxon, given its cuneate leaf bases and shorter inflorescences; its identity is uncertain from the digital image.

A specimen allegedly from Tahiti by an unknown collector (Anonymous, « Commun à Tahiti » ([P05094318])) was identified (but not annotated) by some other person. Although its relatively large inflorescence resembles that of the type specimen, its different leaf morphology and the distance between Tahiti and New Caledonia (c. 4700 km) together make such an identification unlikely.

Figures

FIG. 14. — Distribution maps of Gossia conspicua (Guillaumin ex Vieill.) N. Snow, comb. nov., G. katepahiensis N. Snow, sp. nov., and G. kuakuensis (Baker f.) N. Snow.

FIG. 15. — A-C, Gossia katepahiensis N. Snow, sp. nov.: A, branch with inflorescences; B, flowers in bud; C, detail of flower bud (in longitudinal section at right); D-H, Gossia kuakuensis (Baker f.) N. Snow: D, flowering branch; E, detail of simple cyme (note small leafy bracts at base); F, detail of flower (minus petals and stamens); G, young fruit and leaf;H, older branch with attached leaf showing dark,more or less rectangular cracking in epidermal layers; I, J, Gossia mandjeliaensis N. Snow, sp. nov.: I, flowering branch (detail of cracking outer epidermal layers (lower left) and abaxial oil glands (upper left)); J, flower from above (lacking petals and stamens) (left) and laterally (right). Vouchers: A-C, McPherson 5690 (WELTU – from 2 sheets); D-F, Compton 930 (BM); G, Vieillard 2171 (P); H, Vieillard 2218 (P); I-J, McPherson 2551 (P). Scale bars: A, D, 2 cm; B, E-G, 5 mm; C, J, 3 mm; I, 2 mm. Scale bar lacking: H, leaf c. 5 cm long.