Goniothalamus hmoope Munzinger & D.M. Johnson, 2023

Munzinger, Jérôme, Johnson, David M. & Saunders, Richard M. K., 2023, Novitates neocaledonicae XIV: A third species of Goniothalamus (Blume) Hook. f. & Thomson from New Caledonia and lectotypification of G. obtusatus (Baill.) R. M. K. Saunders, Adansonia (3) 45 (20), pp. 327-335 : 328-332

Goniothalamus hmoope Munzinger & D.M. Johnson , sp. nov.

( Figs 1 ; 2 )

Goniothalamus species distinguished from congeners by the combination of a truncate apex of the anther connective, narrowly cylindrical and slightly bifid funnel-shaped stigma, narrowly oblong (dactyliform), torulose monocarps with up to eight seeds, and mucilaginous trichomes on the testa.

TYPUS. — New Caledonia. Province Nord, Mandjélia, above Puébo [Pouébo], forested slopes, c. 700 m, [20°23’58.2”S, 164°31’40.188”E], 3.XII.1982, bud, fr., G. McPherson 5249 (holo-, P [ P01987649 ]! ; iso-, GH!, K, L [ L.1761617 ] !, MO!, NOU! [NOU012381]!, RSA!).

PHENOLOGY. — Flowers in March-June, November, and December, fruits in April, May, and October-December.

HABITAT. — Goniothalamus hmoope sp. nov. grows in dense humid forest at low and medium elevation, sensu Jaffré et al. (2012) at elevations of 300- 720 m. The species can be locally abundant; it was observed as the second most numerous species among trees larger than 5 cm DBH in a 400 m 2 plot located at Dawenia ( Munzinger 2013).

DISTRIBUTION. — The plant appears to be endemic to the Northern Province of New Caledonia. All the collections come from the Mont Panié (the northernmost population is Mandjélia) and Ton-Non (Roches de la Ouaième) massifs, except for one from the Plateau de Tango, towards Mont Grandié, which is a little off-centre in the south ( Fig. 3 ).

CONSERVATION STATUS. — The species is known from the “Réserve de nature sauvage du mont Panié” protected area. The calculated EOO is 205 km 2 and the AOO is 40 km 2. Some subpopulations may be threatened by introduced browsers, and those at lower altitudes may also be threatened by fire. Goniothalamus hmoope sp. nov. was assigned a risk of extinction status of Vulnerable by the New Caledonian Red List Authority on 28 Sept. 2022 ( Endemia & RLA Flore NC 2022).

VERNACULAR NAME. — Hmoope (Nemi language) ( Munzinger 2013).

ETYMOLOGY. — The specific epithet refers to the vernacular name.

PARATYPI. — New Caledonia. Mt. Panié, above Haut Coulna, on SW forested slopes, 700-720 m, 20°36’49”S, 164°44’24”E, 26.X.1999, fr., McPherson & van der Werff 17741 (MO, NOU[NOU012355], P [ P 00507387]) ; Mandjélia, above Puébo, forested slopes, 600- 700 m, [20°23’58.2”S, 164°31’40.188”E], 15.IV.1984, fl., young fr., McPherson 6466 ( P [ P 01987634], MO[MO 3224998]) ; Vallée du Ruisseau Faiya (affluent de la Ouaième) au-dessous du Col de Kouiri, 300 m, [20°39’21”S, 164°49’21”E], 18.IV.1966, fl., MacKee 14721 ( P [ P 01987624]) ; Haut Diahot, Tendé, 500-600 m, exploitation forestière Frouin, [20°24’37”S, 164°31’19”E], 12.XII.1968, (bud, fl., fr.), MacKee 19978 ( P [ P 01987630, P 01987631]) ; ibid., 500 m, [20°24’26”S, 164°31’31”E], 31.III.1969, fl., MacKee 20461 (NOU[NOU012462], P [ P 01987629]) ; ibid., 600 m, [20°24’37”S, 164°31’19”E], 16.V.1981, fl., fr., MacKee 39054 (NOU[NOU012461], P [ P 01989352]) ; ibid., 600 m, [20°24’37”S, 164°31’19”E], 30.VI.1982, bt., fl., MacKee 40573 ( P [ P 02034823]) ; Wewec, parcelle 1, 640 m, 20°35’0.594”S, 164°43’38.3”E, 7.XI.2010, fl., fr. Munzinger 6192 (NOU[NOU063369], P [ P 00871530, P 06901166]) ; Wewec, [20°35’56”S, 164°43’50”E], c. 300 m, 7.XI.2010 (fl., fr.) Munzinger (leg. Folger) 6199 (NOU[NOU063376]) ; Parcelle Dawenia 1, 608 m, 20°32’26.4”S, 164°40’40.8”E, 12.XI.2010, fr., Munzinger et al. 6262 (NOU[NOU063441]) ; Parcelle Dawenia 2, 619 m, 20°32’17.7”S, 164°40’57.9”E, 13.XI.2010, fl., Munzinger et al. 6273 (NOU[NOU063452]) ; La Guen, cascade (Panié), 637 m, 20°37’29”S, 164°46’40”E, 22.XI.2010, fl., Munzinger 6464 (NOU[NOU063644], P [ P 06901165]) ; La Guen, [20°37’28”S, 164°46’57”E], [580 m], 23.XI.2010, fl., Munzinger 6475 (NOU[NOU063655], P [ P 04021461]) ; Massif du Mandjélia, exploitation forestière Frouin, [20°23’47.76”S, 164°31’41.48”E], [c. 700 m], 16.IV.1981, fl., young fr., Suprin 1216 (NOU[NOU012382, NOU012383]) ; Mandjelia, piste de la tour radio, 20°24’0.45”S, 164°31’33.3”E, [c. 700 m], 16.III.2010, fl., Vandrot 296 (NOU[NOU053914]) ; Plateau de Tango, en direction du Mont Grandié, 24.I.2013, 20°58’48”S, 165°6’0”E, [c. 400 m], fl., Vandrot 671 (NOU[NOU083129]) ; Wagap, 1861-1867, fr., Vieillard 2283 ( P [ P 01987561, P 01987563]) .

DESCRIPTION

Shrub or small tree 4-10 m tall, DBH up to 23 cm. Buds initially rusty-pubescent, twigs soon glabrate, gray-green to greenish brown, soon gray, longitudinally wrinkled. Lamina of larger leaves 6.3-12.0 cm long, 2.4-3.7 cm wide, (sub)coriaceous or rarely chartaceous, paler beneath, narrowly elliptic to oblong-oblanceolate, base cuneate and short-decurrent, apex obtuse to acute, margins slightly revolute, glabrous above, very sparsely short-pubescent to glabrate and punctate below; midrib plane to slightly impressed above, raised below; secondary veins 10-16 per side, at midpoint of leaf diverging at 45-80° from the midrib, weakly brochidodromous, indistinct to slightly raised above, slightly raised below; higher-order veins indistinct to slightly raised above, slightly raised below. Petiole 4-8 mm long, (0.7-)0.8-1.2(-1.5) mm wide, shallowly canaliculate in cross-section, sparsely pubescent to glabrate. Inflorescences of 1 or 2 flowers, arising from leaf axils or from short tubercles on leafless older twigs or directly on trunk (cauliflory); pedicels (12-) 15-27 mm long, 0.6-0.7 mm thick at midpoint, thicker at apex, sparsely pubescent to glabrate, bearing 3 or 4 basal bracts, the uppermost attached 2.5-3.3 mm above the pedicel base, 1-1.5 mm long, triangular, acute, slightly concave, sparsely to densely pubescent. Sepals free, 3-4.2 mm long, 3.6-4.2 mm wide, triangular, acute, sparsely pubescent. Petals green with purplish base in vivo; outer petals 19- 23 mm long, 7-8 mm wide, fleshy, lanceolate, apex acute, margins recurved, fine-pubescent on both surfaces; inner petals 8-9.5 mm long, 5-6 mm wide, fleshy, connivent over the stamens and carpels, rhombic to ovate-acuminate, trigonous in apical 1/3, appressed-pubescent externally, the pubescence shorter and finer along the margins, pubescent on connivent margins internally, glabrous and somewhat corrugated on the inner concavity. Stamens ca. 100, 1-1.4 mm long, oblong-clavate to quadrate, anthers 6-8-locellate, anther connective apex truncate, pubescent in center, papillate on periphery; filament rudimentary. Carpels 10-12; ovaries 1.8-1.9 mm long, oblong, glabrous; ovules 6-8 in a single row; stigma articulated at the apex of the ovary, 1.7-1.9 mm long, narrowly cylindrical and slightly bifid funnel-shaped. Torus of flower 3.1-3.7 mm in diameter, 1.2-1.5 mm high, glabrous, ovary bases slightly sunken in center. Fruit of 7-12 monocarps borne on a pedicel 16-25 mm long, 1.8-3 mm thick, longitudinally wrinkled, glabrate; torus of fruit 10-13 mm in diam., 6-7 mm high, depressed-globose; monocarps green (immature?) in vivo, 4.5-6.6 cm long, 0.7-1.1 cm wide, narrowly oblong (dactyliform), torulose, basally tapered gradually into a hollow stipe 4-10 mm long, apex contracted into a distinct beak 3-12 mm long; pericarp 0.5-0.6 mm thick. Seeds up to 8 per monocarp, usually 5-7, lying parallel or slightly oblique to the long axis, in a single row, 8.7- 10.1 mm long, 6-7.1 mm wide, 5.4-6.8 mm thick, brown, ellipsoid, covered by a thin shiny fragile layer than upon wetting becomes pubescent and mucilaginous; micropyle obscured by pubescent arilloid mass.

NOTES

Revisionary work on Asian-Pacific Annonaceae in recent years led to the recognition that the Asian genus Goniothalamus is represented on New Caledonia. Van Heusden (1996) proposed that Richella A. Gray , represented in New Caledonia by R. obtusata (Baill.) R. E. Fr. ( Fries 1959; van Steenis 1964), was not distinct from Goniothalamus , and their resemblance had previously been noted by Jessup (1988). This was subsequently supported by the molecular phylogenetic study ofNakkuntod et al. (2009), leading to the nomenclatural transfer of R. obtusata to Goniothalamus made by Saunders & Wang (2011) after the generic name Goniothalamus (Blume) Hook.f. & Thomson ( Hooker & Thompson 1855) had been conserved ( Saunders 2009) against Richella A. Gray (1852) . In the meantime, a new species from New Caledonia was described as G. dumontetii R.M.K.Saunders & Munzinger ( Saunders & Munzinger 2007) .

In the phylogenetic study of Goniothalamus by Nakkuntod et al. (2009) the New Caledonian species G. dumontetii and G. obtusatus (Baill.) R.M.K.Saunders were retrieved in the same subclade as the new species described here. The analysis of Tang et al. (2015a) did not include material of G. hmoope sp. nov., but the other two species again fell in the same strongly supported subclade, which also included G. australis Jessup from Australia, not included in the earlier study. The New Caledonian species did not group with sampled taxa from New Guinea or Fiji in either study, as might have been expected, but instead were part of a clade comprising species from mainland Southeast Asia and nearby areas. The only synapomorphy identified for members of this Austro-Caledonian subclade by Tang et al. (2015a) was the pubescent testa, which also occurs in G. hmoope sp. nov. (not included in the analysis). While all three species are endemic to the main island “Grande-Terre” of New Caledonia, only G. obtusatus is widespread, while G. dumontetii is restricted to the centre, and G. hmoope sp. nov. has the smallest distribution, restricted to the north-east ( Fig. 3 ).

Goniothalamus hmoope sp. nov. resembles G. australis Jessup ( Jessup 1986) in its narrow elliptic leaves and relatively small inner petals compared to outer petals, but has a much narrower fruit. On the basis of its morphology, the new species would be classified in G. subgen. Truncatella Bân ( Bân 1974) ; the analysis of Tang et al. (2015b) showed, however, that recognition of this subgenus was not consistent with their phylogenetic results.

In some localities Goniothalamus hmoope sp. nov. is sympatric with Xylopia vieillardii Baill. , which it superficially resembles in habit, leaf shape, and leaf size. In the presence of flowers and/or fruits, the two species are readily distinguishable; when sterile, X. vieillardii may be distinguished from G. hmoope sp. nov. by its architecture type (main axis with spiral branching, see Johnson [2003], versus distichous in G. hmoope sp. nov.), conspicuous white lenticels on the twigs, the more prominent tertiary vein reticulum on the lower leaf surface (absent in G. hmoope sp. nov.), and the occasional presence of two branches from the same leaf axil (always absent in G. hmoope sp. nov.) ( Johnson et al. 2013).

Goniothalamus hmoope sp. nov. can be distinguished from its New Caledonian congeners using the following key and Fig.4 :

Figures

FIG. 1. — Goniothalamus hmoope Munzinger & D.M. Johnson, sp. nov.: A, flower, side view with one outer petal removed; B, habit; C, seed, view from micropylar end; D, seed, side view; E, outer petal, adaxial view; F, inner petal, adaxial view; G, stamen, abaxial view; H, carpel, ovary dissected to show row of ovules; I, Flower with petals and most of stamens removed, showing sepals, three stamens, six carpels, and torus. A, E-I, based on McPherson 6466 (MO3224998); B-D, based on McPherson 5249 (MO3208807). Drawing by Kate Stenger. Scale bars: A, B, 1 cm; C-F, 5 mm; G-I, 1 mm.

FIG. 2. — Field photos of Goniothalamus hmoope Munzinger & D.M. Johnson, sp. nov.: A, trunk with slash; B, adaxial face of leaves; C, abaxial face of leaves; D, inflorescence borne on trunk (cauliflory); E, flower from below; F, cauliflorous fruit; G, ramiflorous fruit seen from above. (Photos; A-C, F, G, © Ph. Birnbaum; D, E, © P. Lowry).

FIG. 3. — Distribution of Goniothalamus spp. in New Caledonia. G. hmoope Munzinger & D.M. Johnson, sp. nov. (z), G. dumontetii (z), G. obtusatus (z). Abbreviation: T, type specimen. Gray represents ultramafic substrates; slanting lines represent low elevation dense humid forest (Jaffré et al. 2012); dotted area in zoom is the “Réserve de nature sauvage du mont Panié” protected area; dotted lines indicate 500 m elevational intervals. A dynamic distribution map is available: http://u.osmfr.org/m/936288/

FIG. 4. — Field photos of the three species of Goniothalamus (Blume) Hook.f. & Thomson in New Caledonia: A, B, G. dumontetii R.M.K.Saunders & Munzinger: A, leaves; B, fruits;C, D, G. hmoope Munzinger & D.M. Johnson, sp. nov.; C, leaves;D, fruit;E, F, G. obtusatus (Baill.) R.M.K.Saunders; E, leaves; F, fruit. Photos: A, © J. Munzinger; B, Ch. Davidson; C, D, © Ph. Birnbaum; E, F, V. Hequet.