Alyxia humboldtensis Lannuzel & Gâteblé, 2024

Lannuzel, Guillaume, Munzinger, Jérôme, Vandrot, Hervé & Gâteblé, Gildas, 2024, Alyxia Banks ex R. Br. in New Caledonia: a clarification of several species complexes, nomenclatural notes, and a description of three new species, Phytotaxa 649 (1), pp. 1-43 : 10-15

Alyxia dolioliflora Guillaumin (1958: 398) . Holotype:— NEW CALEDONIA, Two miles south of Pouembout, elev. 200 m, 16 July 1952, MacMillan 5108: P [P00072136!]; isotypes: A [A02180217!], BISH [BISH500605], E [E00086582], K [ K000894167 !], L [L0004670!] ( Figs 3 , 5 )

Species circumscription: — Alyxia dolioliflora was considered as a distinct species by Boiteau (1981), and then included in A. tisserantii by Middleton (2002). We follow Boiteau (1981) and keep it as a distinct species characterized by linear leaves, red bark, and fruit articles longer than they are wide. Some specimens (e.g. MacKee 16935, Munzinger 7856) of A. tisserantii s.l. (as circumscribed here) can be confused with A. dolioliflora . However A. dolioliflora differs from A. tisserantii by a longer corolla tube (2.5–4.1mm vs 1.1–2.1 mm), and longer fruit articles (8–9.5 mm vs ca. 4.2–5.1 mm). Alyxia dolioliflora is most similar to A. minimiflora and A. rosmarinifolia , but differs from both by a longer corolla tube (2.5–4.1 mm vs 0.8–1.6 mm), and from the former by being entirely glabrous. As circumscribed here, the species grows only on serpentinites, at the low altitude foot of ultramafic mountains in the central part of the western coast of Grande Terre. In this region, it is easily recognizable as it forms typical shrubs with erect linear leaves. One must however be careful, as it can be confused with some forms of A. tisserantii , at the margins of its distribution. A closer look at the fertile parts then becomes conclusive.

Distribution and habitat:— A. dolioliflora is distributed from Poya to Kaala-Gomen, at low altitude (0–300 m elev.) on ultramafic substrates. It grows mainly in shrublands.

Phenology:— From herbarium specimens and pictures available, A. dolioliflora is flowering and fruiting from October to July, and seems to be sterile in August and September.

Specimens examined:— NEW CALEDONIA; North province: Presqu'île de Gatope , 20°58'47"S, 164°39'50"E, 23 October 2012, Butin 266 bis ( NOU081790 !) ; Pouembout, Tiaoué , elev. 50 m, 26 February 2004, Dagostini, Rigault & Fambart-Tinel 835 ( NOU003016 !, P04551201!) ; s.l., 1874, Germain s.n. (P04225736!); Mt Koniambo , 21 December 1950, Guillaumin 9512b (P04225738!) ; Kaféaté , 27 December 1950, Guillaumin 9630 (L.3729894!, P04225726!) ; Oundjo , 15 January 1974, Jaffré 1214 (L.2702461!, NOU058240 !, P04225717!, P05236784!) ; Tinip , elev. 50 m, 20 May 1956, MacKee 4627 (E00098761, L.2711052!, P04237019!) ; Voh: Mt. Katépahié , elev. 400 m, 20 January 1963, MacKee 10071 ( CANB 146007.1 !, L.2702420!, NOU058232 !, P04225709!) ; Oundjo , elev. 50 m, 8 May 1966, MacKee 14905 (L.2699544!, NOU058233 !, P04225749!) ; Voh : base du Mt. Katépahié, elev. 30 m, 12 October 1965, MacKee 13607 (L.2702434!, P04225754!) ; Tinip , 5 July 1966, MacKee 15191 (L.2711050!, MO1114518 , NOU058037 !, P04237018!) ; Pouembout : Base W Plateau Tiéa, elev. 30 m, 22 May 1967, MacKee 16813 (L.2702419!, MO1114516 !, NOU058302 !, NOU058303 !, P04225816!) ; Mt Kopéto ( Pente Nord ), elev. 400–800 m, 6 July 1967, MacKee 17097 (L.2699557!) ; Oundjo , 26 January 1970, MacKee (Leg. Déméné) 21482 ( NOU058031 !, P04225597!, P04237011!) ; Kone: Pinjen , elev. 50 m, 25 April, 1971, MacKee 23568 (L.2711049!) ; Pouembout , elev. 30 m, 16 February 1972, MacKee 25018 (L.2699514!, NOU058304 !, P04225595!) ; Pouembout , elev. 30 m, 16 February 1972, MacKee 25019 ( NOU058305 !, P04225594!) ; Oundjo , elev. 0–50 m, 17 February 1972, MacKee 25040 (L.2699543!, P04225596!) ; Mt Koniambo , elev. 100m, 24 April 1974, MacKee 28530 (L.2699538!, P04225587!, P05236797!) ; Tiéa ( Pente Ouest ), elev. 50 m, 27 December 1974, MacKee 29554 (L.2702431!, MO1114514 , P04225583!) ; Pouembout : Base W Tiéa, elev. 50 m, 11 April 1975, MacKee 30028 (L.2702418!, NOU058306 !, P04225550!) ; Voh: Katepahie, elev. 50 m, 1 January 1976, MacKee 30566 (L.2699519!, L.2699520!, MO1114578, P04260832!), Poya: Avangui , elev. 300 m, 2 January 1976, MacKee 30617 (L.2699563!, NOU058171 !, P04225546!) ; Voh: Tieta , elev. 50 m, 20 May 1977, MacKee 33175 (L.2711048!, NOU058028 !, P04237010!) ; Tinip , elev. 150 m, 22 January 1979, MacKee 36482 ( BISH745438 !, L.2702462!, NOU058307 !, P04225534!, P04225538!, P04551288!) ; Voh: Tahafé , elev. 200 m, 12 April 1979, MacKee 36765 ( BISH745436 , L.2702441!, NOU058308 !, P04551240!, P04225535!, P04551241!) ; Cap Deverd, South of Kaala-Gomen , elev. 30 m, 22 December 1983, McPherson 6208 ( MO420962 !, NOU058181 !, P04236830!) ; Base du Koniambo, 16 December 1973, Jaffré 1267 ( NOU058239 !, P04236776!) ; Vavouto , elev. 45 m, 18 December 2002, Jaffré & Roumagnac 3583 ( NOU058226 !, P04551199!) ; Tiéa , S of Pouembout, elev. 90 m, 18 November 2015, Lowry 7411 ( MO100880167 , MPU312388!, NOU082432 !) ; 2 miles south of Pouembout , elev. 200 m, 1952, McMillan 5108 ( BISH500605 , E00086582!, K000894167 !, L 0004670!, P00072136!) ; Mt, Koniambo , elev. 150 m, 7 January 1983, McPherson 5323 ( MO421093 , NOU058313 !) ; Oundjo , 15 September 1966, Schmid 1442 ( NOU058238 !, NOU058295 !, P04225564!, P04225565!, P05236779!) ; Oundjo , 15 September 1966, Schmid 1442 bis ( NOU058294 !) ; Koniambo Ouest, elev. 50 m, 19 December 1972, Schmid 4341 ( NOU058296 !), Koné, cimetière Oundjos , 25 November 1967, Sévenet 345 (P04551311!) ; Koniambo , elev. 100 m, 12 February 1974, Sévenet 589 ( NOU058297 !) ; Ouaco-Tinip , 4 November 1975, Sévenet & Boiteau 1100 ( NOU058231 !, P04226203!) ; Near Oundjo , 10 November 1959, Thorne 28017 (P04225559!) ; 7 km S of Pouembout , 20 October 1959, Thorne 28025 (P04225560!) ; Pouembout Goyeta, 26 May 1982, Toutain 3486 ( NOU058310 !) ; Gatope , 1861, Vieillard 2766 (P04220361!, P04225811!) ; Gatope , 1861, Vieillard 2970 (P04220355!) ; Pum, Tanlé, Vieillard 951 ( K000894170 !, L 0064516!, L 0004669!, NY345468!, NY345469!, P00156869!, P00156870!, P00156871!, P00156872!, P00156873!, P00156874!, P00156875!) ; Gatope, Vieillard 952 ( BM000508454 !, K000894169 !, P00156867!, P00156868!) .

Alyxia humboldtensis Lannuzel & Gâteblé , sp.nov. ( Figs. 4 , 5 ), (urn:lsid:ipni.org:names: 77336418-1)

Diagnosis:— Alyxia humboldtensis is a small procumbent vine characterized by its leaves, generally in whorls of 4–5. It is similar to A. leucogyne in being the only species with more than 3 leaves per whorl, but differs from it by the adult plant’s size, sessile leaves, short and reduced inflorescences and apparently glabrous fruits. Flowers are twice as long (ca. 8 mm vs 4 mm in A. leucogyne ), with yellowish corolla (white in A. leucogyne ).

Type:— NEW CALEDONIA, South Province, Mont Humboldt , elev. 1500 m, 21°52'58"S, 166°25'19"E, 2 February 2022, Lannuzel & Pouget 568, holotype: NOU [ NOU108492 !] ; isotype: P [P01139694!]

Procumbent liana, up to 50 cm, stems covered by ca. 0.1 mm hairs; latex white. Leaves verticillate in whorls of 3–5, coriaceous, green adaxially, light green abaxially, strongly revolutate, sessile, lamina oboval to spatulate, 24–27× 13–18 mm; base attenuate to rounded, apex retuse, mucronate, both surfaces minutely pubescent, covered with 0.1 mm hairs, leaf venation not visible apart from the midrib. Flowers axillary, grouped in reduced dichasial cymes, axes green, sparsely pubescent, ca. 1.3 mm, pedicels null to ca. 0.5 mm. Narrowly triangular bracts, ca. 2.5 × 1 mm, green, margin ciliate.

Flower 5-merous, 7.8 × 1.8 mm. Calyx lobes slightly spreading from corolla, narrowly triangular, acute at apex, ca. 3.5 × 1 mm, green, glabrous, with margin ciliate toward apex. Corolla pale yellow, tube ca. 4.5 × 1.5 mm, glabrous outside, with only 1 ring of hairs inside, below anthers and stigma, composed of 0.1 mm long appressed hairs, lobes sinistrorse, lanceolate, glabrous, erected at anthesis.

Anther cone 1 mm long, not exserted; filaments 0.2 mm long, inserted at 2/3 of tube length. Ovary ca. 0.6 × 0.5 mm, very hairy around base with 0.2–0.3 mm long hairs, style 1.5 mm long, glabrous, stigma ovoid, acute, hairy at top. Mature fruit unknown. From young fruits, mericarps seem to present 1–2 ovoid articles.

Distribution and habitat: — Alyxia humboldtensis is known from only one population, located near the Mont Humboldt summit, at 1500 m elev. It grows as a procumbent liana in the cyperaceous vegetation between peridotite rocks.

Phenology:— From herbarium specimens and pictures available, the species seems to flower in December and January. Immature fruits were seen in February.

Etymology:— The species is named after the mountain where the only population is known, Mont Humboldt.

Specimen examined:— NEW CALEDONIA: South province; Mont Humboldt , elev. 1500 m, 21°52'58"S, 166°25'19"E, 13 December 2013, Gâteblé. 410 ( NOU092221 !) .

Alyxia kaalaensis Boiteau (1979: 446) . Holotype:— NEW CALEDONIA, pente sud du Mt Kaala , elev. 400m., 10 October 1965, MacKee 13599: P [P00072140!]; isotype: P [P00143138!] ( Figs 6 , 7 )

Species circumscription — Alyxia kaalaensis has received several recircumscriptions over time, leading to wide or narrow distributions. We accept the species as plants bearing dense pubescence on young parts, oblong to orbicular leaves, and rounded fruit articles. It is most similar to A. nummularia , probably leading to different concepts, but differs from it by subterminal inflorescences, and a corolla tube> 3 mm long. The known species distribution is around Mont Kaala, north of Grande Terre. At first sight, specimens from the top of the mountain and from low altitude were considered as different species, the former with orbicular leaves, and the latter with oblong ones. However, detailed investigation, along with flower dissections, showed no significant differences between both morphotypes’ fertile parts. We thus kept one species ranging from low to high altitude in the region of Mount Kaala. The specimens referred to as “ A. sp. cfr. caletioides ” in Guillaumin (1957) and assigned to A. kaalaensis by Middleton (2002) correspond better to A. oppositifolia .

Distribution and habitat:— The species is known only from Kaala-Gomen and Koumac, on the hills of Siounda, Mont Kaala and Mont Ouazangou (from pictures only for the latter locality). It grows in shrublands from 20 to 950 m elev.

Phenology: —From herbarium specimens and pictures available, A. kaalaensis is flowering from March to October, and fruiting from February to October.

Specimen examined:— NEW CALEDONIA: North province; Koumac, Kokondo , 25 February 2004, Dagostini 814 ( NOU002995 !) ; Massif du Kaala , elev. 740 m, 8 November 2005, Dagostini, Rigault & Barrière 1064 ( NOU010215 !) ; Mt Kaala , elev. 850 m, 20°36'28''S, 164°22'44''E, 21 June 2017, Lannuzel 46 ( NOU088511 !) ; Mt Kaala , Au-Dessus du Captage, elev. 180 m, 20°39'3''S, 164°23'31''E, 11 January 2018, Lannuzel 145 ( NOU089023 !) ; Mt Kaala , elev. 800 m, 20°36'28"S, 164°22'44"E, 04 July 2018, Lannuzel 184 ( NOU089182 !) ; Base W Mt Kaala , elev. 50 m, 20 May 1956, MacKee 4618 (P04237016!) ; Pente W Mt. Kaala , elev. 100 m, 8 September 1958, MacKee 6490 (P04236963!) ; Pente W Mt Kaala , elev. 100 m, 8 September 1958, MacKee 6506 (P04237013!) ; Western slope of Mt Kaala , elev. 100 m, 8 September 1958, MacKee 6507 (P04237014!) ; Pente Sud du Mt. Kaala, elev. 400 m, 10 October 1965, MacKee 13568 (P04236962!, P04551337!); Pente S Mt Kaala , elev. 400 m, 10 October 1965, MacKee 13599 (P00072140!, P00143138!) ; Sommet Nord du Mt Kaala, MacKee 16127 (L.2702413!); Pente du Mt Kaala au dessus de Gomen, elev. 500 m, 21 April 1967, MacKee 16656 ( NOU021996 !, P05236808!, P05391603!) ; Koumac: Siounda, 22 April 1967, MacKee 16663 (L.2711051!, NOU058035 !, P04237015!), Koumac: Siounda , elev. 200 m, 13 May 1978, MacKee 35149 ( CANB 721982.1 , L.2699329!, NOU058036 !, P04236967!, P05236819!) ; Koumac: Kokondo , elev. 20 m, 13 May 1983, MacKee 41470 (L.2699330!, NOU058127 !, P04259046!, P04551336!) ; Base Kaala Versant Ouaco , 4 November 1975, Sévenet-Pusset 1102 ( NOU058038 !, P04237012!) .

Alyxia loeseneriana Schlechter ( 1906: 237) . Lectotype, designated by Middleton (2002:32):— NEW CALEDONIA, Auf den Bergen bei Ou-Hinna, elev. 800 m., 7 January 1903, Schlechter 15689: P [P00072143!] ( Fig. 7 )

= Alyxia johnsoniae Moore (1921: 358) . Holotype:— NEW CALEDONIA, Mont Mou , 13 March 1914, Compton 543: BM [BM000508534!]

= Alyxia vieillardii Boiteau (1979:452) . Lectotype (designated here):— NEW CALEDONIA, Balade, Vieillard 961: P [P00072144!]; isolectotypes: P [P00143131!; P00143132!], L [L0544776!]

Notes:— In the protologue of Alyxia vieillardii, Boiteau (1979) wrote that the type specimen was “ Vieillard 961, bord de rivière à Balade (riverside at Balade), (holo-, P)”. There are at least six specimens of Vieillard 961 at P and one at L. Two of them (P00228423! and P04223453!) belong to the genus Ochrosia Juss. and one (P00143133!) is not labelled “bord de rivière à Balade” so they can be excluded from the type material. A lectotype and three isolectotypes are then designated in accordance with Middleton’s 1997–1999 notes on the specimens.

Species circumscription:— Boiteau (1981) and Middleton (2002) had a concept of Alyxia loeseneriana which included Alyxia loeseneriana var. macrocarpa Boiteau , the latter only known from specimens bearing fruits. Flowering specimens collected after Boiteau’s description of the variety or not seen by him (not held at P) shows this variety deserves to be elevated to the species level (see under A. paniensis nom. nov., stat. nov.) because of different flower morphology. The concept of A. loeseneriana is thus narrowed to specimens with corolla tubes 3–5 mm long, and fruit articles ca. 1.5 cm long, with rounded apices.

Distribution and habitat:— This species is quite common on Grande Terre, mostly on non-ultramafic substrates and sometimes on ultramafic ones, from 50 to 1000 m elev. It grows almost exclusively in dense humid forest, but can be seen at forest edges.

Phenology:— From herbarium specimens, A. loeseneriana is flowering from October to February. Fruits were collected all year round so they probably mature slowly.

Specimens examined:— NEW CALEDONIA: North province; Sud de Canala , 1 November 1869, Balansa 2436 (P04237304!, P04237305!) ; Col Amieu , 11 February 2005, Barrabé 277 ( NOU004587 !) ; Pouébo , 15 September 1949, Cheeseman 3153 (P04237261!) ; Haute vallée de la Tchamba, elev. 100 m, 15 January 1966, MacKee 14251 (L.2711018!, NOU058079 !, P04237282!) ; Massif Ton-Non , elev. 800 m, 21 March 1968, MacKee 18518 (P04237263!) ; Massif Ton-Non , elev. 900 m, 13 July 1968, MacKee 19176 (P04237262!) ; Table Unio , elev. 900 m, 14 November 1970, MacKee 22882 (L.2711013!, NOU058098 !) ; Col D’Arama , elev. 60 m, MacKee 25969 (L.2711014!, P04237251!) ; Tiwaka: Entre Bopope et Pombei , elev. 250 m, 30 October 1973, MacKee 27666 (L.2711019!, NOU058080 !, P04237250!) ; Haute Tchamba , elev. 500 m, 8 March 1977, MacKee 32890 ( NOU058083 !, P04237283!) ; Haute Tipindjé , elev. 900 m, 27 December 1990, MacKee 45273 ( NOU058101 !) ; Mt. Colnett , elev. 1000 m, 29 October 2003, McPherson 19061 (P04551208!) ; Mt. Colnett , elev. 950 m, 1 November 2003, McPherson 19122 (P04551209!) ; Tiébaghi Massif , elev. 550 m, 20 December 1983, McPherson 6167 ( MO421107 , NOU058071 !, NSW 238708, P04237259!) ; Roches de la Ouaième, elev. 619 m, 20°38'26''S, 164°52'15''E, 1 November 2010, Munzinger 6094 ( NOU063272 !) ; s.l., Pancher s.n. (P04237273!); Gatope , s.c. 2960 (P04237281!) ; Auf den Bergen bei Ou-Hinna , elev. 800 m, 7 January 1903, Schlechter 15689 (P00072143!) ; Route de Gomen à Konio , 21 December 1966, Schmid 1900 ( NOU058077 !) ; Mont Ignambi , elev. 1000 m, 19 August 1965, Veillon 431 (P04237266!) ; Mont Panié , elev. 900 m, 7 July 1978, Veillon 3609 (P04237265!) ; Bord de rivière à Balade , Vieillard 961 (L 0544776!, P00072144!, P00143131!, P00143132!) ; Balade , Vieillard 961 (P00143133!) ; Gatope , 1861, Vieillard 2960 (P04237277!) ; Gatope, 1861, Vieillard 2961 (P04237280!), Kanala, 1861, Vieillard 2962 (P04237274!) ; Gatope , 1861, Vieillard 2963 (P04237269!) ; Gatope , 1861, Vieillard 2965 (P04237255!) ; South province; Forêts situées au dessus de la Ferme-Modèle ( Nouméa ), 1 October 1868, Balansa 212 (P04237306!) ; Mont Mi , 20 February 1869, Balansa 1399 (P04237307!, P04237252!, S-PL-20399!) ; Forêts situées au NE de la Conception, elev. 700 m, 24 January 1869, Balansa 1404a (P04237301!, P04237303!) ; Monts Koghis , elev. 500 m, 1965, Blanchon 8 (P04237268!) ; Tendo , 21 August 1974, Bourret 12 ( NOU058082 !) ; Mt Mou , 13 March 1914, Compton 543 ( BM000508534 !) ; Me Ammeri , 30 November 1950, Guillaumin, Baumann-Bodenheim & Hürlimann 9075 (L.3729966!) ; Mt. Mou , 2 February 1951, Guillaumin, Baumann-Bodenheim 10141 (L.3718458!, P04237267!) ; Mt. Bouo , 20 April 1950, Guillaumin, Baumann-Bodenheim & Hürlimann 12609 (L.3729994!) ; Mt. Bouo , 20 April 1950, Guillaumin, Baumann-Bodenheim & Hürlimann 12611 (L.3729993! L.3729995!) ; Mt. Bouo , 20 April 1950, Guillaumin, Baumann-Bodenheim & Hürlimann 12650 (L.3735012!) ; Mt Bouo , 20 April 1951, Guillaumin, Baumann-Bodenheim 12651 (P04237257!) ; Tonghoue , 24 January 1971, MacKee 23281 (L.2711009!) ; s.l., Hürlimann 125, (P04237270!); Route de la Ouenghi, elev. 100 m, 16 December 1970, Jaffré 430 ( NOU058067 !) ; Près de La Foa 1910, Le Rat s.n. (P04237271!) ; s.l., Le Rat s.n. (P04237272!); Mt. Koghi: Vallée Thy , elev. 200 m, 24 December 1955, MacKee 3632 (E00075715!, L.2711011!, P04237300!, P04237302!) ; Mt. Koghi , MacKee 4005 (L.2711017!) ; Koh , 1 October 1967, MacKee 17764 (P05391652!) ; Canala: Sentier Ciu-Koindé , elev. 300 m, 5 December 1967, MacKee 18079 (L.2711020!, NOU058078 !, P04237285!) ; Tonghoué , elev. 100 m, 24 January 1971, MacKee 23281 ( MO1114225 , NOU058076 !, P04237284!) ; Thio: Vallée De Koua , elev. 200 m, 23 June 1977, MacKee 33333 (L.2711010!, MO1114562 , NOU058081 !, P04237253!, WAG.1475204) ; Mt Koghis , elev. 850 m, 27 October 1979, McPherson 1984 ( MO1574039 , NOU021989 !) ; Monts Koghis , elev. 500 m, 14 January 1965, Schmid 8 ( NOU057968 !) ; Mt Koghis , elev. 950 m, 7 December 1967, Veillon 1543 (P04237254!) ; Paita, au nord du pic Nondoué , elev. 50 m, 4 April 1991, Veillon 7356 ( NOU058180 !) ; Port de France , 1855, Vieillard 959 (P04237275!, P04237276!, P04237278!)

Figures

FIGURE 3. Alyxia dolioliflora with detail of immature fruits (A), flowers (B), habit (C) and a fertile branch (D). Photographer: G. Lannuzel, from Lannuzel 530.

FIGURE 4. Alyxia humboldtensis, with detail of immature fruits (A), flowers (B), habit (C), and a flowering branch (D). Photographers: G. Lannuzel (A & C from Lannuzel & Pouget 568), C. Laudereau (B & D).

FIGURE 5. Known distribution of Alyxia dolioliflora (dots) and Alyxia humboldtensis (squares). Symbols with “T” represent type specimens. Grayed areas represent ultramafic substrates.

FIGURE 6. Alyxia kaalaensis with detail of a fruiting branch (A), buds (B), habit (C) and a flowering branch (D). Photographer: G. Lannuzel from Lannuzel 184.

FIGURE 7. Known distribution Alyxia kaalaensis (dots) and Alyxia loesneriana (squares). Symbols with “T” represent type specimens. Grayed areas represent ultramafic substrates.