Alyxia oppositifolia Boiteau ( 1979: 452)

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 : 20-21

Alyxia oppositifolia Boiteau ( 1979: 452) .

Holotype:— NEW CALEDONIA, Vallée de la Koumac , elev. 30 m, 19 April 1967, MacKee 16599: P [ P00072115 !]; isolectotype: P [ P00625018 !], L [ L 0544770 !], K [ K000894177 !], NOU [ NOU005731 !] ( Figs 11 , 12 )

Species circumscription: — A. oppositifolia was described by Boiteau (1979) and then maintained by Boiteau (1981) and Middleton (2002). This species’ concept however varied between the two authors, resulting in varying distribution and ecology. We accept a broad concept of A. oppositifolia , characterized by usually opposite leaves, sometimes ternate, flowers usually solitary, sometimes in simple inflorescences of three flowers, with a corolla tube 4.3–7.8 mm long, borne by a peduncle of at least 6 mm, and a fruit article longer than 7–7.5 mm. Lamina shape varies from flat and lanceolate chartaceous leaves, to linear revolutate and coriaceous ones. Pubescence is also variable with glabrous plants and plants pubescent on young stems, leaves, and peduncles. This variation appears to be correlated with substrates, with glabrous plants on calcareous substrates and pubescent ones on serpentine outcrops. These differences could cover two species, but further studies are needed to reach a conclusion on this point.

Distribution and habitat:— A. oppositifolia occurs only in the northwestern part of Grande Terre, at low altitude (0–300 m) shrublands and sclerophyllous forests, on various substrates.

Phenology:— From herbarium specimens and pictures available, flowers can be seen from September to May. Fruits were collected almost all year round.

Specimens examined:— NEW CALEDONIA: North province; Dôme de Tiébaghi , 22 January 1965, Blanchon 1453 ( NOU058274 !) ; Pouembout : conservatoire botanique de Tiéa, 03 October 2000, Dagostini 243 ( NOU058270 !, P05391656!) ; Abhang des Pic de Koné , 08 February 1925, Däniker 1153 (P04257739!) ; Koumac , elev. 50 m, 20°35'7"S, 164°18'50"E, 18 November 2018, Fleurot 503 ( NOU090187 !, NOU105606 !) ; Oua Tilou Mt. , 13 April 1951, Guillaumin & Baumann-Bodenheim 12223 (L.3735039!, P04236964!, US2316613 !) ; Oua Tilou. , 13 April 1952, Guillaumin & Baumann-Bodenheim 12248 (L.3735066!, P00072196!, US2316614 !) ; Oua-Tilou , 13 April 1951, Guillaumin & Baumann-Bodenheim 12264 (L.3735067!, P04236966!) ; OuaTilou , 13 April 1951, Guillaumin & Baumann-Bodenheim 12274 (L.3735068!, P04236965!, US2316617 !) ; Mt Koniambo , 21 December 1950, Guillaumin & Baumann-Bodenheim 9512a (L.3718456!, P00072195!) ; Pindaï, Baie des Sapins , 5 March 2007, Hequet 3597 ( NOU016947 !) ; Massif du Boulinda, 10 July 1973, Jaffré 1158 ( NOU058279 !, P04225718!) ; Massif du Boulinda, Col de Nékoro , 09 November 1972, Jaffré 2172 ( NOU058280 !, P04225715!) ; Gatope , elev. 141 m, 16 November 2004, Labat 3498 ( NOU011192 !, P00454760!) ; Vallée de Koumac , elev. 30 m, 19 April 1967, Mackee 16599 ( K000894177 !, L 0544770!, NOU005731 !, P00072115!, P00625018!) ; Poya: Avangui , elev. 100 m, 11 April 1969, MacKee 20524 ( NOU058179 !, P04260812!, P05236799!) ; Vallée de Poya, Ndokoa , elev. 100 m, 07 May 1971, MacKee 23714 ( NOU058092 !, P04257740!, P04257741!) ; Koumac: Ruisseau Grande Forêt , elev. 250 m, 01 December 1972, MacKee 25996 (P04257738!) ; Néhoué: Babouillat , elev. 30 m, 28 December 1972, MacKee 26110 (L.2699540!, P04260799!) ; Koumac: Grande Forêt , elev. 250 m, 25 March 1973, MacKee 26481 ( NOU058096 !, P04257745!, P04257746!) ; Base Sw du Mt Koniambo, elev. 150 m, 10 April 1975, MacKee (leg. Veillon) 30007 ( NOU058287 !, P04260797!, P04551368!) ; Gomen , crête rocheuse calcaire, 16 July 1977, MacKee 33500 ( NOU058095 !, L.2711324!, P04257743!, P04257744!) ; Koumac: Siounda , elev. 30 m, 13 May 1978, MacKee 35137 ( NOU058094 !, P04257737!) ; Paagoumène , elev. 100 m, 7 July 1978, MacKee 35402 (L.3735063!, P04260794!, P05236768!) ; Massif de Tiébaghi , elev. 5 m, 23 May 1980, McPherson 2709 ( NOU058093 !, P04456360!) ; Presqu'île de Pindai , elev. 5 m, 11 December 2003, Mouly 216 ( NOU050749 !) ; Ouéholle , 17 August 1967, Nothis 439 ( NOU058097 !, P04257742!) ; Paagoumène , 21 August 1967, Nothis 544 ( NOU058189 !, P04260814!) ; Rochers calcaires au-dessus de la Koumac, 20 December 1966, Schmid 1872 (P05391647!, P05391648!) ; Homedeboa , elev. 314 m, 20°44'5"S, 164°32'34"E, 12 September 2018, Vandrot 1450 ( NOU106034 !, P00936759!) .

Figures

FIGURE 11. Alyxia oppositifolia with detail of an immature fruit (A), flower (B), sterile branch (C) and fertile branch (D). Photographer: G. Lannuzel, A & C from Moindah valley, B & D from Tiéa.

FIGURE 12. Known distribution Alyxia oppositifolia(dots) and Alyxia paniensis (squares). Symbols with “T” represent type specimens. Grayed areas represent ultramafic substrates.