Xylopia dibaccata Däniker

Johnson, David M., Munzinger, Jérôme, Peterson, Julie A. & Murray, Nancy A., 2013, Taxonomy and biogeography of the New Caledonian species of Xylopia L. (Annonaceae), Adansonia (3) 35 (2), pp. 207-226 : 218-219

3. Xylopia dibaccata Däniker

( Figs 1 N-O; 4)

Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich 76: 161 (1931). — Type: Neu-Caledonien. “im Tälchen zwischen den beiden Kaalagipfeln, 28.II.1925 (fl, fr), Däniker 1281 (holo-, Z photo!; iso- Z (2), photo!).

DISTRIBUTION AND PHENOLOGY. — This species occurs at scattered locations on the island, but always associated with serpentinites, i. e. in areas of relatively more metamorphosed and hydrothermally altered ultramafic geology. It is found in sclerophyll forest at elevations of 50-200 meters but does not seem common anywhere within its range. Specimens with flowers have been collected from November through February, and those with fruits in February, March, October, November, and December. Colors of seeds and fruits in vivo are not known.

CONSERVATION STATUS. — Xylopia dibaccata shows an EOO of 7556 km 2 and an AOO of 81 km 2. There are nine sub-populations, and none of them is included in a protected area. Two of these are in areas with mining activity with future impact on vegetation. As the plant is restricted to serpentinites, the calculated EOO is a gross overestimate. The plant is never abundant, even in the localities known. Xylopia dibaccata is assigned a preliminary status of Vulnerable (VU: A3cd, B1ab(i, ii, iii)2ab(i, ii, iii)).

MATERIAL EXAMINED. — New Caledonia. La partie supérieure du bassin du Dotio, XII.1871, Balansa 3529 (P[P00507376, P00507377, P00507378], as to fruiting material).— Route du Col d’Amieu à la Mégropo, II.1906, Le Rat & Le Rat 2811 (P[P00507345]). — Nakety, Mokoué, 21.XII.1966, MacKee 16112 (MO, NOU) . — Basse Tontouta , 24.II.1976, MacKee 30741 (MO, NOU) . — Tiwaka , entre Pombei et Bopope, X.1971, MacKee 24389 ( NOU) . — Poindimié , Povila, 200 m, 18.I.1974, MacKee 28147 ( NOU) . — Dothio River valley , along road and trail by river leaving highway, SW of one-way stretch, 50-100 m, 26.I.1983, McPherson 5397 (GH, K, MO, NOU) . — Route Tiwaka-- Koné, 11.II.1977 (fl), Morat 5310 ( NOU) . — Tontouta , 23°46’58”S, 166°16’22”E, 31.X.2004, Munzinger & McPherson 2526 ( NOU) . — Poya-- Nétéa , 3.III.2007, Munzinger et al. 4171 (MO, NOU) . — Avangui , propiété Johnson, 165°04’45”E, 21°19’15”S, 12.XI.2007, Munzinger et al. 4690 ( NOU) . — Dothio , vers 150 m, 26.I.1983, Pusset-Chauvière 490 ( NOU) . — Thio , Haut Dothio, vers 200 m, 20.X.1988, Veillon 6980 ( NOU) . — Poya Nord , entre Le Creek Hervouet et son affluent nord; au-dessus de la Rt 1 vers 40-50 m, 21.X.1998, Veillon 8148 (NOU, P[P00507320]) .

DESCRIPTION

Tree or shrub up to 9 m tall; double-branching occasional.Twigs light gray to brown, initially densely appressed golden-pubescent, the hairs 0.1-0.2 mm long, but soon glabrate, lenticellate.Lamina of larger leaves 6.2-9.7 (-11.6)cm long, 2.8-4.6(-5.4) cm wide, shiny olive-green to brown above, dull, pale brown below, coriaceous, elliptic, elliptic-oblong, or ellipticobovate, broadly cuneate to rounded and slightly decurrent on petiole at the base, obtuse, rounded, or retuse at the apex, glabrous above, sparsely appressedpubescent to glabrate below; midrib slightly raised or impressed to plane above, plane to slightly raised below; secondary veins 8-13 per side, at midpoint of leaf diverging at 45-70° from the midrib, irregularly brochidodromous, these and higher-order veins raised and forming a prominent reticulum on both surfaces.Petiole 3-7 mm long, shallowly canaliculate adaxially,longitudinally wrinkled, sparsely pubescent to glabrate. Inflorescences of 1-3 flowers, axillary or from the axils of fallen leaves; pedicels 1.8-4 mm long, 1-1.5 mm thick, straight, rusty-pubescent; bracts usually 2, the uppermost 0.8-2 mm long, clasping the pedicel, crescent-shaped or semicircular, apex rounded, rusty-pubescent. Buds conical.Sepals ¼-½ connate, 1.8-3 mm long, 2-3.2 mm wide, broadly ovate to triangular, rounded at the apex, rusty-pubescent externally, with a strip of hairs traversing the base but otherwise glabrous internally. Outer petals fleshy, 6.1-9 mm long, 2.5-3.3 mm wide, lanceolate to narrowly ovate or oblong-lanceolate,acute to obtuse at apex, slightly keeled on both surfaces but concave at base on inner surface, appressed-pubescent inside and externally; inner petals fleshy, 6.5-7.0 mm long, 1.5-1.9 mm wide, linear-lanceolate, acute at apex, keeled and pubescent externally, flat and pubescent on inner surface except for the deeply concave and glabrous base. Stamens c. 100; fertile stamens 0.5-1.1 mm long, quadrate, oblong, or clavate; anthers septate at anthesis, with 4-7 locules; apex of connective dome-shaped to flattened, overhanging anther thecae, papillate; filament ¼-⅓ length of most stamens; innermost stamens staminodial, c. 5, 0.5-0.8 mm long, pentagonal or quadrate; staminal cone evident, 1.5-2 mm in diameter, 0.5-0.9 mm high. Carpels 4-6; ovaries 0.5-1 mm long, pressed together, oblong, golden-tomentose; stigmas loosely spreading, 2.2-3.8 mm long, filiform but tortuous and tentacle-like, glabrous, the apex acute. Torus of flower 2-2.4 mm in diameter, glabrous except for hairs on carpellate portion. Fruit of up to 5 monocarps borne on a pedicel 7-9.5 mm long, 1.5-2 mm thick, brown, glabrate; torus of fruit c. 3-5 mm in diameter, 2-3.5 mm high; ovoid, hemispheric, or subglobose; monocarps 2.7 cm long, 0.9 cm wide, 0.9-1.0 cm thick, oblong-ellipsoid to subglobose,verrucose, glabrate, at the base contracted into a broad stipe 5-6 mm long and 3 mm thick; apex obtuse. Seeds 2-4 per monocarp, 12.5-13.1 mm long, 6.0- 6.8 mm wide, 3.9-5.0 mm thick, oblong-ellipsoid, wedge-shaped in cross-section, with a corky ring encircling the micropyle.

REMARKS

Xylopia dibaccata closely resembles X. vieillardii in its short broad monocarps and conical flower buds and is difficult to distinguish from it, a task made further difficult by the limited number of specimens available for study. It appears to be a species of slightly lower elevations restricted to serpentinite sites. The shiny upper surface of the leaf and the rusty pubescence of the pedicels, bracts, and calyx seem to be consistent differences between the two species; in addition, X. dibaccata tends to have only 1-2 flowers per inflorescence, while X. vieillardii commonly has 3-4. No specimens with dehisced monocarps have been seen. The specimen Guillaumin & Baumann-Bodenheim 12128 (A, NY) (Vallée supérieure de la rivière Voh, 250 m, 12.IV.1951), both sheets of which are sterile, may represent this species.

Figures

FIG. 1. — The New Caledonian species of Xylopia L.: A, B, X. pallescens Baill.; A, habit with fruit; B, habit with flowers;C-H, X. vieillardii Baill.; C, carpels and surrounding staminal cone with a few stamens still attached; D, fruit; E, leaves; F, seed, view from micropylar end; G, seed, side view; H, flowers; I-M, X. pancheri Baill.; I, habit; J, fruit; K, stigmas, stamens, and sepals, side view; L, seed, view from micropylar end; M, seed, side view;N-O, X. dibaccata Däniker; N, habit with young fruit; O, habit with flowers; A, B, Veillon 4730 (OWU); C, McPherson 6281 (MO); D, E, McPherson 6330 (MO); F, G, Brinon 1130 (NOU); H, from Sarlin 322 (P00507339); I, McPher- son 3575 (MO); J, McPherson 5976 (MO); K-M, MacKee 29715 (P00507360); N, Munzinger & McPherson 2526 (NOU); O, McPherson 5397 (MO). Scale bars: A, B, D-J, L-O, 1 cm; C, K, 3 mm. Drawing by Kate Ball.