PDF Revision of Ixora (Rubiaceae) in the Marquesas Islands (French Polynesia)

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Revision of Ixora (Rubiaceae) in the Marquesas Islands (French Polynesia)

DAVID H. LORENCE

¹

*, WARREN L. WAGNER

²

, ARNAUD MOULY

^3,4

and JACQUES FLORENCE

⁴

1National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, HI 96741-9599, USA

2Department of Botany, MRC-166, National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC 20013-7012, USA

3National Herbarium, Department of Systematics and Evolution, UMS-CNRS 2700 Taxonomy and Collection, Muséum national d’Histoire naturelle – Phanérogamie CP39, 16 rue Buffon, 75231 Paris 05, France

4US 084 BIODIVAL, Institut de Recherche pour le Développement, Muséum national d’Histoire naturelle – Phanérogamie CP39, 16 rue Buffon, 75231 Paris 05, France

Received November 2006; accepted for publication August 2007

During the preparation of theVascular Flora of the Marquesas IslandsandFlore de la Polynésie française, four new species ofIxoraL. (Rubiaceae) have come to light and are described and illustrated herein:Ixora jourdaniiMouly

& J.Florence,Ixora tahuataensis Mouly & J.Florence,Ixora uahukaensisLorence & W.L.Wagner, andIxora uapouensisLorence & W.L.Wagner. In addition to these new taxa, the following three species ofIxorapreviously described from the Marquesas are recognized: Ixora marquesensis F.Br., Ixora ooumuensis J.Florence, and Ixora spathoideaF.Br. As the Marquesan environment is under serious threat from human impact, feral animals and weeds, the conservation status was estimated for eachIxoraspecies. It is concluded that all Marquesan taxa are in need of inclusion in the IUCN Red List, their status ranging from endangered to critically endangered.

ADDITIONAL KEYWORDS:conservation – endemism – Ixoreae – myrmecophily.

INTRODUCTION

Ixora L. (Rubiaceae, Ixoreae) is a large genus of Rubiaceae comprising about 300–400 species, with the greatest diversity in Asia, especially Malesia (Mabberley, 1997). The genus representatives are easily recognizable from members of Pavetteae (Pavetta L. and Tarenna Gaertn. in the Pacific Islands) by the articulation of the petioles (De Block, 1998). Most species are shrubs or small trees with white, pink, orange or red entomophilous flowers, contorted corolla lobe aestivation, bilocular ovary, each locule with a single ovule attached peltately to the septum, and red or purple drupaceous fruits with

usually two plano-convex pyrenes (Smith & Darwin, 1988; Burger & Taylor, 1993). The genus (and all members of the tribe Ixoreae) is characterized by the

‘ixoroid pollen presentation mechanism’ (Bremekamp, 1966; Nilsson et al., 1993; Puff et al., 1996), meaning the pollen is deposited on the upper part of the style outside of the closed stigmatic lobes before the flower bud opens. At anthesis, the pollen mass is raised above the corolla and made available for dispersal by the stylar pollen presenter before the stigma lobes spread and become receptive (Robbrecht, 1988; Smith

& Darwin, 1988).

Although the genus is widely distributed, there are many endemic species in various Pacific archipelagos, such as Fiji with 21 endemics (Smith & Darwin, 1988) and the Society Islands with seven (Welsh, 1998).

Following the taxonomic framework of Bremekamp

*Corresponding author. E-mail: [email protected]

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(1937), Smith & Darwin (1988) concluded the indigenous Fijian species are referable to three sections of subgenus Pavettoides Bremek. The Marquesan species would seem referable to either of the following two sections: those with three-flowered inflorescences (sometimes more) subtended by a pair of broad, foliaceous bracts (Sect. Phylleilema A.Gray); and those with inflorescences having more than three flowers and bracts not broad and foliaceous (Sect.Pavettopsis Bremek.). In his treatment of the SE Polynesian Rubiaceae, Brown (1935) referred to sect. Phyl- leilema, the two Marquesan species he described, Ixora marquesensis and I. spathoidea.

However, I. marquesensis andI. uapouensis do not fit comfortably into either section because they have broad foliaceous inflorescence bracts (occasionally small and reduced on some inflorescences) and usually more than three flowers per inflorescence (3–10 inI. marquesensis; 5–30 inI. uapouensis).Ixora spathoideais anomalous in having large, spathaceous calyces enclosing the corollas in bud. However, it is important to notice that the circumscriptions of the subgenera and sections of Ixora are unclear and mainly established for the Malesian species. There- fore, we prefer not to assign the Marquesan species to sections pending further study. Nevertheless, all Marquesan species seem clearly referable, in our opinion, to a single group, probably the sect. Phyl- leilema, as their inflorescence morphology is quite similar despite differences in the number of flowers.

We suggest all the Marquesan and other Polynesian species are derived from a common ancestor, and result from a single event of Polynesian islands colo- nization (Mouly, pers. molecular phylogenetic data).

In this revision, we recognize seven species ofIxora from the Marquesas Islands, all endemic to the archi- pelago. Five species are single-island endemics, and Ixora marquesensis is known from three islands, while Ixora jourdaniiis present in two. Ixoraoccurs on seven of the 12 islands and is generally restricted to mesic and wet forest formations at medium to high altitudes (from c. 150–900 m) because much of the lower elevation native vegetation in the Marquesas has been altered or destroyed by human impact, feral animals, fire and invasive alien plant species (Florence & Lorence, 1997).

METHODOLOGY

All measurements given herein are taken from dried herbarium specimens, although certain features such as shapes were supplemented with information from alcohol-preserved flowers and fruits, field notes, and colour slides or digital photos. Measure- ments are presented in the descriptions as follows:

length¥width, followed by units of measurement

(mm or cm). Specimens from the following primary herbaria were studied: BISH, P, PAP, PTBG and US, along with several duplicates distributed to CBG, CHR, L, MO, NSW, NY and S. All specimens cited in this paper have been seen by the authors unless indicated by ‘n.v.’ Additional label data are available at the Flora of the Marquesas Islands website under ‘Specimens’ (http://ravenel.si.edu/botany/

pacificislandbiodiversity/marquesasflora/index.htm).

The following definitions are used in the descriptions. Branchlets are defined as distal, leafy portions of twigs and their diameter was measured at internodes.

Leaf measurements were taken on leaves from branchlets as far down as 7–10 nodes from the branchlet apex. Hypanthium designates the ovary below its point of fusion with the calyx. The calyx limb is differentiated into two parts: the calyx tube repre- senting the fused, tubular part of the calyx free from the ovary, and the calyx lobes for the free distal parts of the calyx. Style measurements include the portion below the two stigmatic lobes. Fruit measurements comprise the pericarp and enclosed pyrenes, and umbo (accrescent calyx and nectary disc). Characters utilized in the key and descriptions are based on mature, fertile specimens, as juvenile material may display consider- able variation in leaf shape and size.

For each species, the area of occupancy (distribution) was calculated using herbarium collection data and field observations, and the conservation status is proposed following the IUCN Red List Category cri- teria (IUCN, 2001).

Orthographic variation exists for certain of the Marquesas Islands. For the sake of consistency, we herein utilize the names accepted by the French Polynesian Government (see the website at: http://

www.presidence.pf) for the islands withIxoraspecies.

In the following list, accepted names are in boldface and alternative spellings are listed in parentheses:

Fatu Hiva(Fatuhiva, Fatu Iva), Hiva Oa (Hivaoa), Mohotani (Motane), Nuku Hiva (Nukuhiva), Tahuata, Ua Huka(Uahuka) andUa Pou(Uapou).

TAXONOMIC TREATMENT GENERIC DESCRIPTION

Shrubs or small trees with leaves opposite and decus- sate, often pink or red when young, blades simple, petiolate or sessile; stipules interpetiolar, slightly connate basally, differentiated into a body and awn, deciduous often leaving a fringe of hair-like colleters.

Inflorescences terminal on branchlets, sometimes on short shoots (brachyblasts) in axillary, ramigerous, or cauligerous position, cymose, sometimes corymbiform with rounded or flattened top, subtended by a pair of reduced inflorescence-supporting leaves, the axes

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often coloured similar to the corollas; flowers mono- morphic, hermaphrodite, protandrous, shortly pedicellate or sessile, not articulate, with calyx 4(5)-lobed, sometimes laciniate or with smaller alternating lobes, persistent or caducous; corolla salverform, with long, slender tube, white or pink when fresh, externally glabrous, sometimes sparsely to densely puberulent, internally glabrous or sparsely puberulent at throat or on lobes; aestivation left-contorted, corolla lobes 4, oblong, wide-spreading at anthesis, stamens inserted

in mouth of corolla tube, exserted, filaments short or lacking, anthers dorsifixed, oblong-ellipsoid, apex acute or apiculate, base sagittate, pollen 3-zono- colporate; ovary 2-locular, each locule with 1 ovule peltately attached to middle of septum, nectary disc present, unlobed; style glabrous or pubescent toward base, stigma lobes 2(3–4), ixoroid secondary pollen presentation present. Fruit drupaceous, ripening red, purple, or black with (1)2 pyrenes; seeds plano-convex or concavo-convex, horny endosperm present.

IXORA JOURDANII MOULY & J. FLORENCE, SP.NOV. (FIGS1, 2)

Type:MARQUESAS ISLANDS: Nuku Hiva. Vainiua, alt. 300 m, 8°48′S, 140°11′W, 2 January 1991, S.

Jourdan 622(Holotype: P; Isotypes: BISH, E, G, K, L, NY, P, PAP, PTBG, S, US).

Diagnosis: Differt a congeneribus Marquesanis sub- sessilibus, erecto-patentibus cordatisque foliis atque magno fructu 12–20¥11–16 mm.

Description:Shrub or tree 2–12 m tall, base of trunk to 6–25 cm diam., entirely pilose except for old branches or nearly glabrous with pubescence restricted to stipules and inflorescence, branches erect-ascending, bark smooth, brown when young, striped whitish-grey or grey-brown when older, branchlets 1.5–2.5 mm diam. Leaves with blade

2.5–14¥2.5–8 cm, ovate to ovate-elliptic, asymmetric, chartaceous to subcoriaceous, glabrous or very densely hirtellous when young, less densely so when older, when fresh glossy dark green above with yellow-white costa, pale green beneath with green- white costa, margins faintly revolute, base auriculate to cordate, amplexicaule, apex acute or shortly acuminate to obtuse, often apiculate, secondary veins 8–10 per side, festooned brochidodromous, tertiary venation conspicuous on both surfaces; petiole absent or 2.5–3.5 mm long; leaves (Nuku Hiva population) on young individuals with blade 12.5–18¥3–6.5 cm, ovate to obovate-oblong or oblong, chartaceous, very sparsely hirtellous, when fresh matt dark green above, pale green beneath with green-white costa, margins faintly revolute, base rounded, apex acute to obtuse or shortly acuminate, secondary veins 9–11 per side, festooned brochidodromous, tertiary and quaternary venation prominulous and conspicuous on KEY TO MARQUESANIXORASPECIES

1a. Plants monocaulous; leaves usually uniform in size along the branchlets, leaf blades 16.5–18.5¥9–10 cm in fertile adult specimens; corolla lobes internally sparsely setulose or hirtellous distally . . . .I. ooumuensis 1b. Plants shrubs or trees with multiple branches; leaves often variable in size along the branchlets, leaf blades mostly less than 16.5–18.5¥9–10 cm in fertile adult specimens; corolla lobes internally glabrous distally or slightly hirtellous from mid-corolla to the apex (Nuku Hiva populations ofI. marquesensis) . . . 2 2a. Calyx limb 33–37 mm long, spathe-like, splitting down one side at anthesis and therefore 1-lobed. . . .I. spathoidea 2b. Calyx limb 0.7–3 mm long at anthesis, cupuliform or shortly tubular (often deciduous in fruit), margin truncate or dentate with usually 4 lobes 0.2–1 mm long . . . 3 3a. Leaves chartaceous; fruit sessile, with calyx tube always persistent, obconic. . . .I. tahuatuaensis 3b. Leaves coriaceous; fruit pedicellate, with calyx tube quickly or tardily deciduous, cylcindric or conic. . . .4 4a. Leaves suberect, sessile or subsessile, blade assymetrical, with base cordate, amplexicaul; fruit with pedicel to 1 mm long . . . .I. jourdanii 4b. Leaves spreading, petiolate, blade symmetrical with base acute, obtuse, rounded, or cordate, not amplexicaul; fruit with pedicel more than 1 mm long . . . 5 5a. Inflorescence (5)10–30-flowered; corolla tube (12)20–50 mm long; fruit ellipsoid, 9–12¥7–10 mm . . . . . . . .I. uapouensis 5b. Inflorescence 3–9(10)-flowered, corolla tube (8)12–20(22) mm long; fruit obovoid or globose, 5–9¥4–9 mm. . . .6 6a. Inflorescence strictly 3-flowered, the two lateral corollas with tubes curved upward and the central one straight; petiole 1.5–3 mm long . . . .I. uahukaensis 6b. Inflorescence (3)6–9(10)-flowered, corolla tubes all straight; petiole (2)4–12 mm long . . . .I. marquesensis

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Figure 1. Ixora jourdanii(glabrous form from Hiva Oa). A, habit, with inflorescence and infructescence. B, inflorescence.

C, base of inflorescence. D, flower at anthesis. E, longitudinal section of flower at anthesis. F, base of flower with corolla removed and calyx partly removed. G, infructescence with single fruit. H, pyrene, ventral and dorsal views. Based on Wood 10244(PTBG).

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Figure 2. Ixora jourdanii(pubescent form from Nuku Hiva). A, habit, with inflorescences and infructescence. B, stipules on young branchlet apex. C, two leaves from young plants. D, floral hairs. E, view of an entire flower. F, corolla lobe.

G, anther, dorsal and ventral views. H, style apex with opened stigma, with detail of hairs. I, fruit. J, detail of hairs on fruit. Based onJourdan 622and652(P, PAP).

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both surfaces; stipules connate basally, the body triangular-ovate, 1.5–3.5 mm long, the awn subulate, 1–2.5 mm long, externally glabrous or very densely hirtellous, internally entirely covered with linear colleters or puberulent and deciduous leaving a fringe of hairs. Inflorescence terminal, 3–4.5¥3–4 cm (including the corollas), cymose-corymbiform, 3–8- flowered, on short peduncle to 5 mm long, subtended by a pair of sessile, cordate, foliaceous, glabrous or densely hirtellous inflorescence-supporting leaves with auriculate basal lobes and pair of stipule-like bracts 1.5 mm long. Flowers on pedicels 1–2 mm long, hypanthium 1.5–2.5 mm long, ellipsoid-cylindrical, very densely hirtellous (Nuku Hiva population) or sparsely spreading puberulent or glabrous (Hiva Oa population), calyx tube 1.5–2 mm long, externally very densely hirtellous (NH) or externally sparsely spreading puberulent or glabrous (HO), internally sericeous, calyx lobes 0.4–1.5 mm long, broadly to narrowly triangular, with tiny extra lobes (NH), externally densely hirtellous, internally sericeous (NH) or externally puberulent or glabrous, internally sericeous (HO);

corolla salverform, white, externally slightly hirtellous from mid-corolla to the apex (NH) or totally glabrous (HO), tube 27–39 mm long, internally glabrous, lobes oblong-elliptic, 7–10¥3–4 mm, internally slightly hirtellous; anthers 3.5–4 mm long, filament 1 mm long, recurved; style 28–40 mm long, pilosulous in basal 2/3, stigma lobes 2–4 mm long. Fruit with pedicel 1 mm long, broadly ellipsoid to obovoid-ellipsoid, 12–20¥9–

16 mm, apex umbonate, hirtellous or glabrous, pink- red to purple when fresh, calyx generally persistent;

pyrenes 6–9¥6–7 mm, globose, obovoid-ellipsoid, plano-convex, slightly mucronate, surface rugose.

Distribution and habitat:This rare and localized new species is known from the N–NW part of Nuku Hiva, in the ‘Terre Déserte’ region where it occurs in mesic forested valleys with Sapindus, Eugenia, Ficus, and Xylosma, at 300–400 m elevation. It is also known from the upper Hanamenu region of Hiva Oa, N-NW of Temetiu in mesic forest withMetrosideros,Crosso- stylis, Cyathea, Freycinetia, and Pandanus and summit shrubland with Weinmannia, Wikstroemia and Psychotria, at 860–884 m elevation.

Phenology: It has been collected in flower and fruit between April and July in Nuku Hiva, and in flower and fruit in July and October in Hiva Oa, where collectors note the flowers are very fragrant. In Nuku Hiva, collectors noted a strange type of flower with deformed, gall-like corollas with variable length of tube and very small, erect lobes. Despite this unusual morphology, the anthers seemed fertile. Ecological observations are needed to understand the associated mechanisms.

Discussion: Among the Marquesan species, Ixora jourdanii is characterized by its erect-spreading leaves with cordate to auriculate, amplexicaul base, 3–8-florous inflorescences, and comparatively large, very fleshy fruits. In the Nuku Hiva population, the vegetative and reproductive organs are entirely hirtellous (Fig. 2). The Hiva Oa representatives, from high elevation crests, differ slightly from the Nuku Hiva specimens by their somewhat larger fruits 17–20¥13–16 mm, larger pyrenes 8–9¥6–7 mm, and their nearly entirely glabrous vegetative and reproductive organs (Fig. 1). The variation in pilosity density inI. jourdanii in Nuku Hiva and Hiva Oa is comparable with the variability found in I. marque- sensis,which has a pubescent form on Fatu Hiva but is glabrous elsewhere. Such infra-specific variability of hair density has been observed several times in Ixora, as in the AfricanI. brachypodaDC. (De Block, 1998). As the twoI. jourdanii populations differ pri- marily by pilosity and are morphologically very similar, they are here interpreted as belonging to one somewhat variable species. Further investigations are needed to elucidate their relationships and may possibly result in recognition of two separate taxa.

Conservation status: IUCN Red List Categories:

Endangered (EN; B2a, B2b i-iii): B2: total area of occupancy less than 500 km²(c. 50 km²). B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. jourdanii on Nuku Hiva (c. 340 km²) and Hiva Oa (c. 315 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals and invasive plants, reducing the extent of the forest.

Paratypes:MARQUESAS ISLANDS: Hiva Oa. Mon- tagnes NW de Temetiu, crête au SE du campement, N de la haute vallée de Hanamenu, 860 m,Schäfer 5907 (BISH, P, US).Nuku Hiva.Terre-Déserte, Pipiheihei, haut versant de Motuhee, alt. 381 m, Butaud &

Bonno 411 (PAP), Butaud & Bonno 412 (P, PAP);

Vainiua, Secteur central de la planèze, alt. 300 m, Jourdan 625(P, PAP, PTBG), Jourdan 652(P, PAP);

Terre-Déserte, Pipiheihei, haut versant de Motuhee, alt. 350–400 m,Mouly 513(BISH, NY, P, PAP, PTBG), Mouly 514 (P), Mouly 515 (BISH, K, NY, P, PAP, PTBG, S).

IXORA MARQUESENSIS F. BR., BERNICE P. BISHOP

MUS. BULL 130: 301, FIG. 50A–H (1935) (FIG. 3) Type: MARQUESAS ISLANDS: Mohotani, jungle in mountains, 150 m, 20 November 1922, W. B. Jones 1728(Holotype: BISH 577886; Isotype: BISH 577885).

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Figure 3. Ixora marquesensis(Nuku Hiva form).A, habit, with inflorescences. B, node showing stipules, petioles, and young leaf pair. C, D, inflorescence-supporting leaves. E, flower at anthesis. F, style, calyx and hypanthium. G, stamen.

Based onFlorence 4354(P).

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Description:Tree to 10 m tall, trunk to 20 cm diam., rarely shrubs; branchlets 1.5–2 mm diam., bark smooth, grey brown to dark brown, glabrous or occasionally densely hirtellous (Fatu Hiva). Leaves with blade 2.5–13 (15)¥1.3–5.5 (8) cm, ovate, elliptic, ovate-elliptic or sometimes obovate-elliptic, chartaceous to coriaceous, glabrous above, glabrous or occasionally hirtellous beneath, especially along the costa (FH), when fresh glossy dark green above with yel- lowish costa, margins plane or faintly revolute, base acute to obtuse, rounded, or cordate, apex acute to obtuse; secondary veins 8–13 per side, festooned brochidodromous, tertiary and quaternary venation prominulous and conspicuous on both surfaces;

petiole (2) 4–12 mm long, glabrous or densely hirtellous (FH); stipules connate basally, body 2–3 mm long, narrowly to broadly triangular-ovate, awn subulate, 0.5–3 mm long, externally glabrous or occasionally hirtellous (FH), deciduous. Inflorescence terminal, subcapitate-cymose, sessile or on peduncle to 5 mm long, 3–9(10)-flowered, subtended by a pair of cordate, sessile or shortly petiolate, reduced inflorescence-supporting leaves and pair of stipule- like bracts to 5 mm long. Flowers sessile or on pedicels to 1 mm long, hypanthium 2.5–3 mm long, ellipsoid or obconical, glabrous or retrorse-strigillose, rarely spreading hirtellous, calyx tube 0.5–2.5 mm long, becoming brown and scarious at anthesis, externally glabrous or hirtellous, internally sericeous, calyx lobes 4(5), variable in size, 0.2–1.2 mm long, subulate to narrowly triangular, externally glabrous to hirtellous; corolla salverform, white, sometimes pink or red-tinged at mouth of tube, tube (8)12–17(22) mm long, externally and internally glabrous, lobes (4)5–12¥1.5–5 mm, oblong-ovate to oblong-elliptic, acute or acuminate; anthers 3–6 mm long, filaments 1–2 mm long; style (10)13–19(25) mm long, pilosulous in basal 2/3, stigma lobes 2–3 mm long. Fruit globose to obovoid, 5–9¥5–9 mm, red when ripe, pedicel 1–2 mm long; pyrenes obovoid-ellipsoid, 4.5–7¥3.5–

6 mm, plano-convex, apiculate, surface rugulose.

Distribution and habitat: Known from Nuku Hiva, Mohotani, and Fatu Hiva. On Mohotani, Ixora mar- quesensis occurs in wooded ravines or open mesic forest or dry forest with Cordia subcordata Lam., Pisonia grandis R.Br., Eugenia reinwardtiana (Blume) DC., and Pandanus tectorius Parkinson at 150–500 m elevation. Collectors note that no regen- eration of this species is occurring on Mohotani as a result of browsing by large populations of feral sheep.

On Nuku Hiva, this species occurs on high ridges and summits at 700–1130 m elevation from Toovii to Terre Déserte in Metrosideros-Weinmannia montane wet forest with Santalum. On Fatu Hiva, it occurs at

c. 700 m elevation in low montane wet forest and shrubland. Collectors note that flowers have a sweet or fruity aroma.

Phenology:Collected in flower from March to Novem- ber and in fruit from May to November.

Discussion: Among the Marquesan species, Ixora marquesensisis characterized by having the shortest corolla tubes. On Nuku Hiva, the length of flowers in one individual or in one inflorescence is extremely variable, with corolla tubes ranging from 10 to 20 mm long (Mouly 504). This species is here interpreted as occurring on three islands and displaying some variability in pubescence. Collections from Nuku Hiva are completely glabrous, whereas those from Mohotani are essentially glabrous except for sparse retrorse strigillose pubescence on the calyx and hypanthium.

Collections from a single population on Fatu Hiva range from being completely glabrous (Wood 10154), to hirtellous on the calyx and hypanthium (Wood 10149), or densely spreading hirtellous on the stems, petioles, and lower leaf surface and spreading hirtellous on the calyx and hypanthium (Wood 10156).

These Fatu Hiva collections do not otherwise differ morphologically from glabrous collections of this species on Mohotani and Nuku Hiva. A similar variability in pubescence is displayed byIxora jourdanii, but in that species the populations are morphologically more consistent.

Endangered (EN; B2a, B2b i-iii): B2: total area of occupancy less than 500 km² (c. 434 km²). B2a, severely fragmented or known to exist at no more than five locations; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. marquesensison Nuku Hiva (c. 340 km²), Fatu Hiva (c. 85 km²) and Mohotani (c. 9 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals, and invasive plants, reducing the extent of the forest.

Additional specimens examined: MARQUESAS ISLANDS: Nuku Hiva. Terre Déserte, 1050 m, Gagné & Montgomery s.n. (BISH 583585). Headwa- ters of the Taipi River, on trail from Toovii to Taiohae, 10 km from Tapuaooa shelter, 700 m, Gillett 2217 (BISH, US); Toovii, Ooumu area, top of Tapueahu Valley off new Hwy, 3500–3700 ft (08°51′S, 140°19′W), Wood & Perlman 4553 (PAP, PTBG, US), 4628 (PTBG), off old Airport road, W of summit crest, W of Peak #1227 m (Tekao), drainages of Tapueahu Valley, 3300 ft,Perlman & Wood 15052(PTBG); partie sud de Toovii, 750 m,Thibault 141(BISH, PTBG, US); Toovii Plateau, 800 m,Dunn 113 (PTBG); Between Taiohae

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Bay and Hooumi Bay, 500–900 m, B. Gagne 1137 (BISH, US); Route Toovii – Terre Déserte, km 4 après le col, 940 m (08°52′S, 140°10′W), Florence 4354 (BISH, K, P, PAP, US); Toovii, épaulement au dessus du réservoir, 865 m (08°52′S, 140°09′W), Florence 4294 (BISH, K, P, PAP, US); Toovii, 2ème vallée au SW du réservoir, 855 m (08°52′S, 140°10′W),Florence 6859(P, PAP); Route Toovii – Terre Déserte, près du col, 800–900 m, Mouly 504 (BISH, P, PAP); Route Toovii – Terre Déserte, près du col, 800–900 m,Mouly 508(P, PAP). Mohotani.West slopes, 280 m, Decker 2796(BISH, CBG, CHR, L, MO, NSW, P, PAP, PTBG, US), 135 m, Decker 2800 (BISH, MO, NSW, P, US), 100 m,Mumford & Adamson 531(BISH); s.l.,F. Hallé 2105 (BISH, P, US); W side above Anaoa, 100 m, Mumford & Adamson 531 (BISH, NY, US), Pacific Entomol. Surv. 537(NY, US); côte nord-ouest, 220 m, Meyer 221 (PAP, PTBG); ‘Plateau’ au-dessus de baie de Mata’ai, 230 m, Schäfer 5315 (BISH, US); partie centrale de l’île, 340 m, Schäfer 5335 (BISH, US), 310 m,Schäfer 5707(US), 300 m,Schäfer 5711(US);

partie méridionale, extrémité S du plateau, 480 m, Schäfer 5718(US); SW shrubland and forested slopes, 150–500 m (09°58′513′S, 138°50′006′W), Wood 10880 (BISH, P, PAP, PTBG, US) (09°59′S, 138°50′W),Wood 10890 (AD, BISH, NY, P, PAP, PTBG, US), Wood 10891 (PAP, PTBG, US). Fatu Hiva. N of Hanativa Valley along ridge crest approaching summit area, 700 m, Decker 2620 (BISH, P, PAP, PTBG, US);

Temeae, south-eastern mesic slopes below Tevaiua, 610 m, Wood 10127 (PTBG), 570 m, Wood 10149 (BISH, P, PAP, PTBG, US), Wood 10154 (BISH, P, PAP, PTBG, US),Wood 10155 (BISH, P, PAP, PTBG, US), Wood 10156(BISH, P, PAP, PTBG, US).

IXORA OOUMUENSISJ. FLORENCE, BULL. MUS. NAT. HIST. NAT., PARIS, SER. 4, SECT. B,

ADANSONIA8(1): 10–11 (1986)

Type: MARQUESAS ISLANDS: Nuku Hiva, épaule- ment Sud du Mt. Ooumu, 8°50′-S, 140°8′W, 830 m, 29 May 1984, J. Florence 6855(Holotype: P).

Description:Monocaulous shrub 1.5 m tall; branchlets c. 4 mm diam., pubescence and bark n.v. Leaves clus- tered toward ends of branchlets, mostly uniform in size with blade 16.5–18.5¥9–10 cm, ovate to ovate- elliptic, subcoriaceous, glabrous on both surfaces, base truncate to slightly subcordate, apex acute to short acuminate, secondary veins 8–10 per side, brochidodromous; petiole 2–3 mm long, glabrous;

stipules externally glabrous, body 4–5 mm long, narrowly triangular, awn 7–9 mm long, subulate.

Inflorescences ramigerous, cymose-fasciculate, sessile, 6-flowered. Flowers subsessile, bracts deciduous, hypanthium subcylindrical, 2.7 mm long, sparsely

hirtellous, calyx tube 3 mm long, obconic, externally sparsely hirtellous, internally strigillose, calyx lobes 4, triangular, 0.7–1 mm long, subequal; corolla salverform, tube 20–23 mm long, externally glabrous, white tinged with pink basally when fresh, lobes 4, 10–12 mm, oblong, apex acute, white when fresh, externally glabrous, internally sparsely setulose- hirtellous distally with white hairs; stamens 4, inserted at top of tube, exserted and reflexed at matu- rity, filaments 1.2–1.5 mm long, flattened, enlarged basally, anthers 5–6 mm long, linear, apex apiculate, base sagittate; style 24–27 mm long, pilosulous in basal 2/3, stigmas 3–3.2 mm long, linear, reflexed.

Fruit and pyrenes unknown.

Distribution: Nuku Hiva. This species has been collected in Metrosideros, Freycinetia and Weinmannia wet forest on ridge crest at 830–950 m elevation.

Phenology: Collected in flower in May.

Discussion: This poorly known species is characterized by its monocaulous habit, large leaves with blades 16.5–18.5¥9–10 cm, and ramigerous or cauligerous inflorescences produced on leafless nodes (Florence, 1986). However, several taxa in Ixoraare known for having occasionally ramigerous inflorescences (Bremekamp, 1937; De Block, 1998), including I. uapouensis (Ua Pou) and I. setchellii Fosberg (Raiatea, Society Islands). Consequently, the inflorescence position of I. ooumuensisshould not be consid- ered strictly ramigerous pending confirmation from additional collections and field observations.

Critically Endangered (CR; B2a, B2b i-iii; D): B2:

total area of occupancy less than 10 km² (c. 5 km²).

B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. ooumuensison Nuku Hiva (c. 340 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals, and invasive plants, reducing the extent of the forest;

D: the rarity of this species is supported by the lack of collections and the small extant area within a commonly collected island, i.e. with a single fertile collection, the authors expect a number of mature individuals lower than 50.

Additional specimen examined: MARQUESAS ISLANDS: Nuku Hiva: Toovii Est, Secteur SSE du Mt. Ooumu, 950 m, 8°51′S, 140°9′W, 1 January 1991, Jourdan 611 (P, PAP).

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IXORA SPATHOIDEAF. BR., BERNICE P. BISHOP

MUS. BULL 130: 303,FIG. 51 (1935)

Type:MARQUESAS ISLANDS: Hiva Oa, S slopes Mt.

Ootua, 800 m, 26 March 1929,E. P. Mumford & A. M.

Adamson 171(Holotype: BISH 577905).

Description: Shrub or tree to 3 m tall; branchlets 3–5 mm diam, glabrous or slightly puberulent, bark brown. Leaves with blade 10–20.5¥9–12.5 cm, ovate to ovate-elliptic, chartaceous, when fresh dark green above with white-green costa, glabrous above, hirtellous on secondary veins and costa beneath, less densely so on surface, base cuneate to obtuse or subcordate, apex acute to abruptly short acuminate, tip rounded; secondary veins 14–15 per side, festooned brochidodromous, tertiary and quaternary venation prominulous and conspicuous on both surfaces; petiole 6–15 mm long, stout, hirtellous; stipules with body 4–6 mm long, narrowly triangular, awn 2–3 mm long, subulate. Inflorescence terminal, capitate-cymose, usually 6-flowered, subtended by a pair of broadly ovate-cordate, short petiolate, reduced inflorescence-supporting leaves c. 6 cm long; flowers sessile or subsessile, hypanthium c. 5 mm long, densely sericeous, calyx limb 33–37 mm long, externally and internally sericeous, spathe-like in bud, the lobes and tube united, at anthesis splitting 1/4–1/3 way down one side to reveal slightly protruding corolla (in bud); corolla in bud red and white, tube c. 17 mm long, lobesc. 17 mm long, contorted; anthers subsessile, attached at mouth of tube, linear- lanceolate, c. 10 mm long; style c. 19 mm long, puberulent, stigmas 2, c. 4–5 mm long. Fruit ovoid, c. 10¥6 mm diam., sparsely puberulent, brown-black (old); pyrenes n.v.

Distribution and habitat:Hiva Oa, collected in mesic evergreen forest with Cyathea, Weinmannia, Glochidion, Metrosideros, Crossostylis andDicranop- teris at 610–800 m elevation. Known only from two collections, this species is rare and imperfectly known. It differs from all other Marquesan Ixora species by its large leaves and unusually long, spathe- like calyx tube that encloses the large corolla in bud.

Mature flowers and pyrenes are not known.

Phenology:Collected in flower (buds) in March and in fruit in July.

B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. spathoideaon Hiva Oa (c. 315 km²) is indicated as

an endangered environment, threatened by human activity (deforestation and fire), feral animals and invasive plants, reducing the extent of the forest; D:

the rarity of this species is supported by the lack of collections and the small extant area within a commonly collected island, i.e. with two collections, the authors expect a number of mature individuals lower than 50.

Additional specimen examined: MARQUESAS ISLANDS: Hiva Oa. Kaava region, south side of main ridge above plantation road, 610 m,Wood 10858 (PAP, PTBG, US).

IXORA TAHUATAENSIS MOULY& J. FLORENCE,

SP. NOV. (FIG. 4)

Type:MARQUESAS ISLANDS: Tahuata, descente de Vaipuha, entre Motopu et Hanapeto, 25 May 1994, J. P. Luce 118 (Holotype: P).

Diagnosis: Differt a congeneribus Marquesanis sarmentosis mirmecophilis ramis, sessili et globoso fructu cum persistente calyce, praecipue differt.

Description:Small ramified shrub with erect, decum- bent or sometimes slightly lianescent branches, glabrous except for inflorescence, bark smooth, grey- brown, branchlets 1.5–3 mm diam. Leaves with blade 15–24¥7–10 cm, elliptic to ovate-elliptic, chartaceous, glabrous, secondary veins 12–15 per side, festooned brochidodromous, tertiary venation prominulous and conspicuous on both surfaces, margins faintly revolute, base obtuse, rounded or subcordate, apex acute, tip abruptly acuminate or mucronate;

petiole 5–6 mm long; stipules minutely connate basally, the body ovate-elliptic, 3 mm long, awn 3 mm long, internally glabrous, quickly deciduous, leaving a large glabrous mark. Inflorescence terminal cymose, 3-flowered, sessile, subtended by a pair of short petiolate, ovate to cordate, inflorescence-supporting leaves 3.5–6 cm long, glabrous, and pair of deciduous stipule-like bracts 2 mm long. Flowers (described from photos) on pilose pedicels 0.5 mm long, hypanthium ellipsoid-cylindrical, spreading hirtellous or pilose, calyx tube 1.5 mm long, obconic, externally spreading-hirtellous or pilose, persistent, calyx lobes 1–2 mm long, triangular, ± laciniate or with small lateral lobes, externally slightly pilose, internally puberulent; corolla salverform, white, apically slightly pinkish in bud, tube 35–43 mm long, externally glabrous, lobes 8–12¥3–4 mm, narrowly ovate- oblong, acuminate, glabrous; anthers 3–4 mm long;

style 37–45 mm long, stigmas 1–2.5 mm long. Fruit globose, 6–7¥5–6 mm diam., puberulent, sessile, calyx tube persistent.

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Figure 4. Ixora tahuataensis. A, habit, with inflorescence and infructescence. B, detail of infructescence. C, fruit.

D, inflorescence-supporting leaf. E, detail of myrmecophilous branchlet. Based onLuce 118(P) and field pictures from J.-F. Butaud (PAP).

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Distribution and habitat: Tahuata. This rare new species is known only from the type collection made above (west of) Vaipuha. It was also observed and photographed in Hanapeto Valley on the east coast of Tahuata at 400–500 m elevation. Ixora tahuataensis occurs in open mesic forest or dry forest withMayte- nus, Sapindusand Psydrax.

Discussion: Because of its myrmecophily, this new species is unique among MarquesanIxora.Ant plants are well known in Rubiaceae, but just a few occur in the subfamily Ixoroideae (Razafimandimbison et al., 2005; Mouly, 2006). A single species ofIxora(ofc. 400 worldwide), the African I. hippoperifera Bremek., is reported as having myrmecophilous leaf sacs (De Block, 1998).Ixora tahuataensis is the second record in the genus having another type of myrmecophilous adaptation. It develops galleries inside the twigs and branchlets with sparsely distributed access holes, thus resembling another ant-plant from Africa, Psydrax subcordata Bridson (Mouly, 2006). The iden- tity of the ant species associated with I. tahuatensis remains unknown, as does its effect on the plant.

Wheeler (1932, 1935) records 29 ant species from the Marquesas, the majority being widespread vagrants and tropicopolitan species, but a few apparently rep- resent indigenous or endemic species or infraspecific taxa. Ixora tahuataensisdiffers also from other Mar- quesan species in having a persistent calyx tube on the fruit (tardily caducous inI. uapouensis).

Phenology: Observed with flower and fruit in May.

Endangered (EN; B2a, B2b i-iii): B2: total area of occupancy less than 500 km²(c. 30 km²). B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. tahuataensis on Tahuata (c. 61 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals and invasive plants, reducing the extent of the forest.

IXORA UAHUKAENSISLORENCE & W.L. WAGNER,

SP.NOV.(FIG. 5)

Type: MARQUESAS ISLANDS: Ua Huka, eastern summit rim of Vaikivi above Hanahouua, 2540 ft (774 m), 8°54.605′S, 139°30.964′W, 26 June 2004, K.

R. Wood 10797 (Holotype: PTBG; Isotypes: BISH, P, PAP, US).

Diagnosis:Differt a congeneribus Marquesanis parvis brevibusque petiolatis cartaceis foliis, parvis stipulis 3.5–4 mm longis, 3-floriferis inflorescentiis, et floribus cum brevi corollae tubo 17–20 mm longo, corollae lateralibus tubis arcuatis.

Description: Tree 2–4 m tall with canopy densely branched, base of trunk to 15 cm diam., glabrous except for stipules and inflorescence, branches erect-ascending, often with sympodial branching, bark smooth, grey-brown, branchlets 1.5–2 mm diam.

Leaves with blade 2–7¥1–3.8 cm, elliptic to ovate- elliptic, chartaceous, glabrous, when fresh glossy, medium green with white-green costa, secondary veins 6–9 per side, festooned brochidodromous, tertiary venation prominulous and conspicuous on both surfaces, margins faintly revolute, base obtuse, rounded or subcordate, apex acute to short acuminate; petiole 1.5–3 mm long, glabrous; stipules connate basally, the body ovate-elliptic, 1.5 mm long, awn 2–2.5 mm long, subulate, externally glabrous, internally puberulent, deciduous. Inflorescence terminal, corymbiform, 2.5–3¥3–4 cm (including the corollas), 3-flowered, sessile or subsessile, subtended by a pair of short petiolate, ovate, reduced inflorescence- supporting leaves 0.6–3 cm long and pair of deciduous stipule-like bracts 1.5 mm long. Flowers on glabrous pedicels 1–1.5 mm long, hypanthium ellipsoid- cylindrical, 1.5–2 mm long, glabrous, calyx tube 0.6–1 mm long, externally glabrous, brown scarious, deciduous, internally sericeous, calyx lobes 4, 0.3–

1 mm long, narrowly triangular-subulate, alternating with smaller subulate lobes, externally glabrous, internally puberulent. Corolla salverform, white, tube 17–20 mm long, externally and internally glabrous, lobes 6–8¥2.5–3 mm, ovate-oblong, glabrous; anthers 3.5–4 mm, filaments 1–1.5 mm long; style 19–22 mm long, pilosulous in basal 2/3, stigmas 1.5–2.5 mm long. Fruit obovoid-globose, 6–7¥5–6 mm, glabrous, pink-red or purple-red when fresh, pedicel 1 mm long;

pyrenes 5–5.5¥4–4.5 mm, obovoid, plano-convex, surface rugulose.

Distribution: Ua Huka. This rare new species is known from only three collections made on the summit rim and plateau regions of Ua Huka at 761–

774 m elevation. Plants were described by the collec- tor as trees densely covered with epiphytic ferns, bryophytes and Freycinetia roots.

Phenology:Collected with flowers and fruit in June.

Discussion: Ixora uahukaensis differs from other Marquesan species in having comparatively small, short-petiolate, chartaceous leaves, small stipules, and 3-flowered inflorescences. Among the French Polynesian species, Ixora uahukaensis most closely resembles I. raiateensis J.W.Moore, but that species has ovate-cordate leaves with longer petioles 4–7 mm long, more numerous flowers with shorter corolla tubes c. 11 mm long, and larger usually ellipsoid fruits c. 12¥5 mm.

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Figure 5. Ixora uahukaensis. A, habit with inflorescences. B, branchlet showing two inflorescences. C, node showing stipules, one leaf removed. D, inflorescence showing one flower at anthesis. E, hypanthium and calyx. F, longitudinal section of flower at anthesis, showing style and ovary, one corolla lobe removed. G, infructescence with two fruits, one inflorescence-supporting leaf removed. H, pyrene, dorsal and ventral views. Based onWood 10797(A, B, D, E, F, G), Wood 10799(C), andWood 10789(H, I, J).

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B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for I. uahukaensison Ua Huka (c. 83 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals and invasive plants, reducing the extent of the forest; D:

the rarity of this species is supported by the lack of collections and the small extant area within a commonly collected island, i.e. with three collections, the authors expect a number of mature individuals lower than 50.

Paratypes: MARQUESAS ISLANDS: Ua Huka:

upper Hanahouua, eastern side of Ua Huka, upper slopes just below eastern summit rim of upper Vaikivi, 8°54′S, 139°30′W, 2200–2540 ft (761–774 m), K. R. Wood 10788(BISH, P, PAP, PTBG, US); eastern summit rim of Vaikivi above Hanahouua, 8°54.605′S, 139°30.964′W, 2540 ft (774 m), K. R. Wood 10789 (BISH, P, PAP, PTBG, US).

IXORA UAPOUENSIS LORENCE & W.L. WAGNER,

SP.NOV.(FIG. 6)

Type:MARQUESAS ISLANDS: Ua Pou: summit ridge around Pou Tetainui, 640 m, 9°40′S, 140°8′W, 18 July 2003,K. R. Wood 10338(Holotype: PTBG; Isotypes: P, PAP, US).

Diagnosis:Differt a congeneribus Marquesanis robus- tis brevibusque petiolatis base obtusa cordataque, subcoriaceis vel coriaceis foliis, et magnis (5)10–30- floriferis terminalibus vel ramigeris inflorescentiis, laciniatis recurvatis calycis lobis, et magna vivide rosea vel rosei-alba corolla.

Description:Shrub or usually a small tree to 5 m tall with diffusely branched canopy, branches erect- ascending or sometimes sprawling, glabrous except for stipules and inflorescence, bark smooth, light brown, branchlets 2–3 mm diam. Leaves with blade (2.5)4–16(18)¥(1)1.5–9(11) cm, elliptic or broadly elliptic to ovate-elliptic, subcoriaceous or coriaceous, glabrous, when fresh glossy, medium to dark green with pale yellow-green costa, secondary veins 6–10 per side, festooned brochidodromous, venation prominulous and conspicuous to tertiary on both surfaces, margins slightly revolute, base obtuse, truncate to subcordate, apex acute; petiole 1–4 mm long, glabrous; stipules connate basally, the body ovate to ovate-elliptic, 3–4 mm long, awn 3–5 mm long, externally glabrous, internally puberulent, deciduous, leaving a fringe of reddish-brown hairs at node. Inflo-

rescence terminal or sometimes ramigerous on short leafy or leafless shoots, corymbiform (5)10–30- flowered, 2.5–6.5¥3–6.5 cm (including the corollas), sessile or subsessile, subtended by a pair of short petiolate, ovate-cordate, reduced inflorescence- supporting leaves 0.8–2 cm long and pair of deciduous stipule-like bracts 5–6 mm long. Flowers often grouped in cymules of 3, on glabrous pedicels 0.5–

1 mm long subtended by subulate bracts 1.5–2 mm long; hypanthium ellipsoid-cylindrical, 2–3 mm long, spreading hirtellous or glabrate, calyx tube obconic, 1–1.5 mm long, externally spreading-hirtellous or glabrate, internally sericeous, calyx lobes 0.5–1.5 mm long, triangular, ± laciniate or with small lateral lobes, recurved, persistent. Corolla salverform, white flushed with pale to deep pink or uniformly pink, tube (12)20–50 mm long, externally and internally glabrous, lobes 9–12¥2–3 mm, narrowly ovate-oblong, acuminate, glabrous; anthers 2.5–3 mm long, filaments 0.5–1 mm long; style (13)22–52 mm long, pilosulous in basal 3/4, stigmas 1–2.5 mm long. Fruit broadly ellipsoid to ovoid-ellipsoid, 9–12¥7–10 mm, umbonate, glabrous, smooth, pedicel 1 mm long, calyx tardily caducous; pyrenes 6–8¥5–7 mm, ellipsoid to obovoid-ellipsoid, plano-convex, surface rugulose.

Distribution and habitat: Ua Pou. This new species occurs in montane evergreen wet cloud forest on slopes and summits of high ridges at 625–900 m elevation with associates including Weinmannia, Metrosideros, Freycinetia, Hibiscus tiliaceus L., Cyathea and Crossostylis. Ixora uapouensis is localized, with small populations often growing in wet gulches near streams.

Phenology:Collected in flower in June, July, Novem- ber, and in fruit in July.

Discussion: Ixora uapouensisdiffers from its Marque- san congeners by its comparatively large and shortly petiolate, basally obtuse to cordate, subcoriaceous or coriaceous leaves, relatively large (5)10–30-flowered, terminal or ramigerous inflorescences on short leafy shoots, large, showy, bright pink or pink-white corollas, and persistent recurved, laciniate calyx lobes.

Endangered (EN; B2a, B2b i-iii): B2: total area of occupancy less than 500 km² (c. 50 km²). B2a, fragmented populations; b (i-iii), habitat continuing decline inferred. The suitable habitat forI. uapouen- sison Ua Pou (c. 105 km²) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals and invasive plants, reducing the extent of the forest.

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Figure 6. Ixora uapouensis. A, habit, with inflorescence. B, inflorescence in bud. C, node with stipules. D, calyx and hypanthium. E, flower at anthesis. F, infructescence with submature fruits, several missing. G, pyrene, dorsal view.

H, pyrene, ventral view. Based onWood 10388(A, C, D, E, F); Wood 10800(B);Wood 6473(G);Meyer 2542(H, I).

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Paratypes:MARQUESAS ISLANDS:Ua Pou.Teava- haakiti, cliffs between Tekohepu and Teavahaakiti, 2300 ft (701 m),Perlman et al. 15895(PTBG); Teava- haakiti, steep slopes of main ridge S of Oave, E facing cliffs between Teavahaakiti and Tekohepu, 2240 ft (683 m), Perlman & Wood 15901 (PTBG); forested slopes around Pou Maka, 671 m, 9°40′S, 140°8′W, Wood 10365(PAP, PTBG, US); valley below Pou Maka trail, 579 m, 9°23.632′S, 140°5.57′W, Perlman &

Holland 19737(PTBG); ridge between Pou Maka and Pou Akei, 634 m, 9°23.573′S, 140°4.865′W, Perlman 19728 (MO, NY, P, PAP, PTBG, US); forested ridge and slopes up to Teavahaakiti, north-west side, 732 m, Wood 10432 (BISH, P, PAP, PTBG, US);

central Ua Pou including the summit crest regions around Oave and the nearby peak of Matahenua, 2950–3030 ft (899–924 m), 9°23′S, 140°04′W, Wood

& Perlman 10800 (P, PAP, PTBG, US); Tekohepo, summit, 2500–3000 ft (884–914 m), 9°24′31′S, 140°04′21′W, Wood & Perlman 6473(PTBG).

NOTES ON CULTIVATED SPECIES In addition to the seven endemic species covered in this key, four Ixoraspecies are commonly cultivated in the Marquesas. All four have inflorescences which lack a pair of reduced inflorescence-supporting leaves, have numerous flowers and possess articulate inflorescence axes, thus placing them in subgen. Ixora.

The cultivatedIxoraspecies may be distinguished as follows.

Ixora caseiHance var.caseiis a shrub 2–3 m tall with shortly petiolate leaves with blade to 20¥8.5 cm and red flowers with a corolla tube 4–5 cm long borne in large, showy, dense inflorescences of c. 50–100 flowers.

Representative specimens examined: MARQUESAS ISLANDS: Fatu Hiva. Omoa village, 10–20 m, Decker 2783 (US). Hiva Oa. Taaoa, partie orientale de la vallée lieu-dit Touhi, 30 m, Schäfer 5594 (US).

Nuku Hiva. Hakaui, environs de l’église, 1 m, 08°55′S, 140°09′W,Florence 4425(BISH, P, PAP, US).

Ua Huka. Vaipae’e village, 0.25–1 km inland from bayhead, beside Lichtle house, 1–10 m, Decker 1682 (P, US).

Ixora coccinea L. is a shrub 1–3 m tall differing by its smaller, sessile or subsessile, basally cordate leaves with blade to 9¥4 cm and red (creamy white or yellow in some cultivars) flowers with a corolla tube c. 4 cm long borne in smaller, less dense inflorescences.

Representative specimens examined: MARQUESAS ISLANDS: Ua Huka. Vaipaee: cultivated in the garden of Pension Chez Alexis Scallamera, 10–20 m,

8°55′49′S, 139°34′34′W, Dunn 343 (BISH, P, PAP, PTBG, US).Hiva Oa.Atuona, 5 m,Sachet 1250(US), Sachet 2159(BISH, US).

The following two additional species with white flowers that are strongly fragrant in the evening are less frequently cultivated.

Ixora finlaysonianaG. Don is a shrub or small tree to 10 m tall with pure white flowers having foliaceous calyx lobes and a corolla tube 3–3.5 cm long.

Representative specimens examined: MARQUESAS ISLANDS: Fatu Hiva. Omoa village, along road in town and in residence yards, 10 m, 10°30.705′S, 138°41.107′W, Perlman 18421(BISH, P, PAP, PTBG, US).Hiva Oa.Atuona, 5 m,Sachet 1275(US).Nuku Hiva. Taiohae, maison de l’Administrateur, 20 m, 08°54′S, 140°06′W,Florence 6919(BISH, P, PAP, US).

Ixora hookeri (Oudem.) Bremek. (syn. I. odorata Hook., nom. illeg. non Spreng.) is a shrub 2–3 m tall with large, openly branched inflorescences and corollas with cream white to yellow lobes and a pink tube 6–7 cm long.

Representative specimens examined: MARQUESAS ISLANDS: Fatu Hiva. Omoa village, 10–20 m, Decker 2784 (BISH, US). Hiva Oa. Atuona, 10 m, Sachet 1279(BISH, PAP, US).

ACKNOWLEDGEMENTS

This study was greatly facilitated by useful dis- cussions, field observations, photos and specimens provided by Dr Jean-Yves Meyer (Délégation à la Recherche, Polynésie française), and Ken Wood and Steve Perlman (National Tropical Botanical Garden). We thank Dr Jean-François Butaud, who provided information on the Marquesas flora. Impor- tant observations and new collections resulted from fieldwork carried out during the 1988 Fatu Hiva expedition and during trips in 1995, 1997, 2003, 2004 and 2005 as part of the ‘Vascular Flora of the Marquesas Islands’ project, which was supported by a generous project donation. We are grateful to the Délégation à la Recherche (Papeete, Tahiti), the Musée de Tahiti et des Iles, and the Service du Développement Rural for logistic support, the Délé- gation for permission to collect in the Marquesas and the Délégation and the Haut-Commissariat de la République en Polynésie française for permission to conduct research. We thank the curators of the following herbaria for loans or permission to study their specimens: BISH, P, PAP, PTBG, US. The illustrations were skilfully drawn by Alice Tangerini (US), Andreas Dettloff and Corinne Ollier (PAP), and Agathe Ravet (P). Liloa Dunn, Tim Flynn,

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Denise Mix, Robynn Shannon and Mike Sission all kindly assisted with specimen processing and databasing. The contribution by WLW to this study was partially supported by the Smithsonian Research Opportunities Fund and while appointed as McBryde Chair at the National Tropical Botani- cal Garden. We wish to thank Petra De Block for valuable suggestions and comments that improved the final version of this paper.

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