Psychotria fambartiae Barrabé, 2014

Barrabé, Laure, 2014, Four new species of Psychotria (Rubiaceae) from New Caledonia, including one presumed to be extinct, Phytotaxa 173 (2), pp. 101-116 : 102-106

Psychotria fambartiae Barrabé , sp. nov. ( Figs. 1 , 2 )

This species is similar to Psychotria montrouzieri Barrabé & J.Florence (in Barrabé et al. 2013: 326), from which it differs principally by the laciniate stipules (vs. bifid in P. montrouzieri ), and the capitate inflorescences with up to eight flowers (vs. pedunculate, slender, with more than eight flowers).

Type: — NEW CALEDONIA. Grande Terre, Province Nord: Poya, Nétéa , Porin Néa , vallée du creek Pwe Païta qui remonte jusqu’à l’ancienne mine, forêt de plaine, bord de creek, zone de transition entre serpentines et roches volcano-sédimentaires, 80–100 m, 21°15’16’’S, 165°11’13’’E, 24 January 2008, L. Barrabé, F. Rigault & J. Munzinger 642 (holotype P!, isotypes K!, NOU-030922!, NOU-030923!, S!) .

Shrub, 0.3–1 m tall, sparsely branched; bark gray to brown when dry, glabrous, smooth to slightly wrinkled; young shoots, petioles, and terminal vegetative buds slightly and sparsely hirsute. Stipules free, broadly triangular, 4.5–9 × 2– 2.5 mm, margins strongly laciniate, with 5–8 lobes, colour unknown, sparsely to densely hirsute, deciduous; colleters not seen. Leaves clustered at ends of branches; petiole smooth, 0.2–0.7 cm long, 0.5–1.25 mm thick, plano-convex; blades obovate to oblong, 2–9.5 × 0.7–3.5 cm, acute to obtuse at apex, acute to round at base (never decurrent), margins entire and narrowly revolute, chartaceous, discolorous when dry, darker and sometimes whitish-variegate on adaxial side, adaxial side polished and glabrous, abaxial side sparsely hirsute; midvein and secondary veins hirsute, midvein channelled and sometimes whitish on adaxial side, raised on abaxial side; secondary veins 8–14 on each side, spaced at 3–11 mm, at 50–75° angle with the midvein, impressed and sometimes whitish on adaxial side, raised on abaxial side; tertiary venation obscure on adaxial side, impressed on abaxial side. Inflorescences erect, capitate, 6–8-flowered, hirsute, sessile. Bracts axillary to each flower, triangular, 5–8 mm long, with laciniate margins, pink to red, slightly hirsute on adaxial side. Flowers 4–5-merous, erect, sessile, heterostylous; flower buds obovoid. Hypanthium turbinate, 1–1.5 × 1–1.5 mm, smooth, pink to red, sparsely hirsute except densely tomentose at base; nectary disk entire, circular, 0.5–0.75 mm in diameter, glabrous, papillose. Calyx chartaceous, pink to red, sparsely hirsute outside, glabrous inside; tube to 3 mm long, colleters lacking; lobes ovate, 2–4.5 × 1–2 mm, obtuse at apex, erect, margins entire. Corolla actinomorphic, hypocrateriform, papyraceous, white, sparsely to densely hirsute outside, entirely glabrous inside; tube straight or sometimes arcuate, 12–27 mm long, throat flared and 2–3 mm wide at mouth, base 0.75–1 mm wide; lobes ovate, 8–12.5 × 3.5–5 mm, acute at apex, perpendicular to the tube (at anthesis), adaxial and abaxial sides smooth. Stamens included to partially included, glabrous; filaments linear, ca. 1 × 0.2 mm, terete, white, fused to corolla ca. 3 mm below the mouth; anthers ovoid, ca. 2 × 0.5 mm, white, dorsifixed near the base. Style filiform, 8–15 × 0.25 mm, terete, white, glabrous. Stigma bilobed, white, papillate, lobes ovoid, to 2 mm long. Fruits ellipsoid, 5.5–12.5 × 3.5–9.5 mm; exocarp smooth, white, densely hirsute when young to sparsely hirsute when ripe; mesocarp unknown. Pyrenes plano-convex, ovoid, 4 × 3 × 1.5–2 mm, obtuse at apex, round at base; dorsal side convex, lumpy, 5-channelled; ventral side flat, slightly lumpy, with a thin raised median crest; pregermination slits lacking, basal aperture present. Endosperm unknown.

Distribution and habitat: — Psychotria fambartiae Barrabé (this publication) occurs in wet forests and vegetation intermediate between wet forest and ‘maquis minier’, which is the local name for a specific type of shrubby vegetation ( Jaffré 1980). This species occurs on soils derived from a mixture of ultramafic and volcano-sedimentary substrates. Herbarium specimens were collected at the bases of three isolated ultramafic massifs close to the north-western coast, Boulinda, Paéoua, and Koniambo, and in the Koné-Tiwaka region, near Bopope, at 100–450 m elevation, within the districts of Poya, Koné, and Poindimié ( Fig. 3 ).

Phenology: —This species appears to flower throughout the year as specimens with flowers were collected in January, February, March, June, August, September and October. Fruiting specimens were collected in January, February, August and September.

Etymology: —This species is named for Jacqueline Fambart-Tinel, who has been curator of the herbarium of Nouméa (NOU) for the last 12 years.

Affinities: — Psychotria fambartiae belongs to the ‘ monanthos’ subclade (Barrabé 2013), which is one of the most diverse lineages in New Caledonia, containing 17 described species: P. bourailensis Guillaumin (1930: 28) , P. calliantha ( Baillon 1879: 229) Guillaumin (1930: 28) , P. coptosperma ( Baillon 1879: 289) Guillaumin (1930: 29) , P. deverdiana Guillaumin (1930: 30) , P. lycioides ( Baillon 1879: 228) Guillaumin (1930: 31) , P. micromyrtus ( Baillon 1879: 291) Schlechter (1906: 261) , P. monanthos ( Baillon 1879: 293) Schlechter (1906: 261) , P. montrouzieri , P. nekouana ( Baillon 1879: 287) Guillaumin (1930: 32) , P. nummularioides Baillon ex Guillaumin (1930: 32) , P. rosmarinifolia ( Baillon 1879: 291) Schlechter (1906: 261) , P. spachiana ( Baillon 1879: 285) Guillaumin ex Barrabé & Mouly (in Barrabé et al. 2013: 346), and four other new ones. All species of this subclade are subshrubs or creeping shrubs; they have leaves less than 10 cm long, bifurcate or laciniate stipules, uni- to multi-flowered, capitate to slender pedunculate inflorescences, white to pinkish corollas, and white to bluish-gray fruits less than 0.5 cm in diameter. Psychotria fambartiae is most similar to P. montrouzieri and P. coptosperma , because all have leaves 5–10 cm long, and inflorescences with more than five flowers. Psychotria fambartiae differs by having its shoots and stem slightly hirsute (vs. tomentose in P. montrouzieri and glabrous in P. coptosperma ), deeply laciniate stipules (vs. bifid), inflorescences capitate and with fewer than eight flowers (vs. pedunculate and with more than eight flowers), bracts and calices deep red to pink (vs. mainly green). In addition, P. montrouzieri is found exclusively on ultramafic substrates, in the archipelago of Belep, and at a single location near the north-western coast of the main island, between the massif of Tiébaghi and Koumac, whereas P. fambartiae and P. coptosperma have broader ecological distributions. Both occur on ultramafic and volcano-sedimentary substrates, in the area of Poya, Koné and Touho for the former ( Fig. 3 ), and throughout the north-western coastal region, and on the Isle of Pines for the latter.

Conservation assessment according to the IUCN Red List categories and criteria: — Psychotria fambartiae is known from seven localities: the south-western base of Koniambo (Rivière Pandanus), the south-western base of Boulinda (Avangui, Mine Saint-Louis, Creek Hervouet), the eastern base of Boulinda (near Nétéa), the centre of Boulinda (area of Grand Boulinda), the base of Paéoua (Forêt Plate), near Bopope, and close to Pombéi. Its extent of occurrence does not exceed 1300 km ². Boulinda, Paéoua, and Koniambo are all ultramafic massifs; the latter is currently being exploited for nickel, and the other two have been mined in the past. Populations of P. fambartiae on these mountains are thus expected to have been adversely affected by mining (dumping of mining waste, opening of roads; Jaffré et al. 1998a, L’Huillier et al. 2010). The other populations are located along the Koné-Tiwaka road where the invasive Pinus caribaea Morelet (1851: 107) has been extensively planted ( Kohler 1984), and now constitutes a major threat to the local vegetation ( Meyer et al. 2006). These populations are also near villages where they are subject to fires that are started to clear land for agriculture and for hunting. Consequently I assign P. fambartiae a provisional status of Vulnerable: VU B1ab(i,ii,iii)+2ab(i,ii,iii).

Paratypes: — NEW CALEDONIA. Grande Terre, Province Nord: Poya, Nétéa , Porin Néa , vallée du creek qui remonte jusqu’à l’ancienne mine, 21°15’3’’S, 165°11’56’’E, 24 September 2007, L. Barrabé, F. Rigault & R. Pourudeu 578 (NOU-029222!); Poya , Nétéa , Porin Néa , vallée du creek qui remonte jusqu’à l’ancienne mine, 130 m, 21°15’6’’S, 165°11’21.4’’E, 1 August 2009, L. Barrabé, R. Clark, O. Weber, N. Sleddon & R. Pourudeu 921 (K!, NOU-034024!, P!); Koné, Koniambo, en contre-bas ouest d’une carrière, affluent nord de la rivière Pandanus, 100 m, 21°1’10’’S, 164°46’37’’E, 17 February 2007, R. Barrière (leg. M. Ducousso) 81 (NOU-016600!); Poya, massif du Boulinda, secteur mine St. Louis , 10 June 1973, T. Jaffré 1175 (NOU-032721!, NOU-032726!); Poya, Boulinda, route de la mine de St. Louis , 150–200 m, 16 January 1974, T. Jaffré 1231 (NOU-032725!); vallée de la Tiwaka, 220 m, 30 January 1987, J. Jérémie & C. Tirel 1788 (P-00752087!); Pouembout, Haute Pouembout, 500 m, 15 February 1968, H.S. MacKee 18433 (P-00752085!); Poya, Avangui, 100 m, 12 February 1973, H.S. MacKee 26230 (P-00752088!); Poindimié, Tiwaka, entre Pombéï et Bopope, 250 m, 30 October 1973, H.S. MacKee 27673 (P-00752089!); Poindimié, Tiwaka, entre Pombéï et Bopope, 250 m, 1 January 1979, H.S. MacKee 36334 (NOU-032724!, P-00752090!); Pouembout, creek Hervouet, propriété Johnston, 10 January 2004, A. Mouly, J. Munzinger, L. Vary, P.P. II Lowry, T. Leborgne & M. Schlessman 294 (NOU-032720!, P-00591897!); Poya, Nétéa, 3 March 2007, J. Munzinger, G. McPherson, M. Tuiwawa, G. Gâteblé, D. & I. Létocart, & R. Amice 4185 (NOU-017201!); Poya, massif du Boulinda, base du Grand Boulinda, 450 m, 26 August 1967, J.-M. Veillon 1271 (NOU-032722!, P-00752092!); transversale Tiwaka-Bopope, 300 m, 30 January 1987, J.-M. Veillon 6306 (NOU-032723!, P-00752091!) .

Figures

FIGURE 1. Psychotria fambartiae Barrabé. A. Branches with inflorescences and young fruits; B. Detail of the abaxial leaf apex; C. Stipule; D. Detail of an inflorescence with flowers at anthesis; E. Young fruit; F. Dorsal face of the pyrene; G. Ventral face of the pyrene; H. Lateral surface of the pyrene; I. Cross section of the pyrene. Drawn by Michèle Magat.

FIGURE 2. Psychotria fambartiae Barrabé. A. Habit; B. Flowers at anthesis. Photos credits: Hervé Vandrot.

FIGURE 3. Distribution map of the four new Psychotria species in New Caledonia. Ultramafic substrates are shaded in gray.