Alyxia minimiflora Lannuzel, sp.nov.
Creators: name: Lannuzel, Guillaume
name: Munzinger, Jérôme
name: Vandrot, Hervé
name: Gâteblé, Gildas
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Apocynaceae
Alyxia
Alyxia minimiflora

description: Alyxia minimiflora Lannuzel, sp.nov. (Figs 8, 10), (urn:lsid:ipni.org:names:77336419-1)
Diagnosis: — Alyxia minimiflora is a small dense shrub characterised by its small linear leaves, and small flowers. It is similar to A. rosmarinifolia (Baill.) Guillaumin by its linear leaves and small flowers, but differs from it by shorter flowers (1.5 mm vs 2 mm in A. rosmarinifolia), a primary inflorescence axis of 1 mm (vs ca 3 mm in A. rosmarinifolia) and densely pubescent young shoots.
Type: — NEW CALEDONIA, South Province, Pic aux chèvres, elev. 270 m, 22°11'38"S, 166°27'37"E, 5 May 2022, Lannuzel, Foord & Pouget 634, holotype: NOU [NOU108945!]; isotype: P [P01139656!]
Small shrub, up to 50 cm, young stems densely pubescent; latex white. Leaves ternate, subcoriaceous, green adaxially, light green abaxially when young, flat, petiole 1.5–2.8 mm long, pubescent, lamina linear, 10–30 × 1.4–2 mm; base cuneate, apex rounded, mucronate, both surfaces looking lustrous but with sparse and very short hairs (ca. 0.01 mm long) on main veins abaxially, leaf venation not visible apart from the midrib. Flowers axillary, grouped in trichasial cymes, axes green, pubescent, null to 1.7 mm, pedicels 0.2 × 0.8 mm covered by 1 caduceous bract, ca. 1 × 1 mm, reddish, pubescent.
Flower 5-merous,1.6–1.9 × 0.5–1 mm. Calyx lobes appressed to corolla, widely triangular, acute to obtuse at apex, ca. 0.5 × 0.5 mm, green, glabrous, but with ciliate margin. Corolla tube pale orange, lobes creamy to yellowish, tube ca. 1.6 × 0.8 mm, glabrous outside, with only 1 ring of hairs inside, below anthers and stigma, composed of 0.2 mm long appressed hairs, lobes sinistrorse, rounded, glabrous with slightly ciliate apex, recurved at anthesis.
Anther cone 0.5 mm long, not exserted; filaments 0.1 mm long, inserted at 2/3 of tube length. Ovary ca. 0.5 × 0.3 mm, hairy at base with 0.1 mm long hairs, style 0.4 mm long, glabrous, stigma ovoid, obtuse, hairy at top. Fruit green then black when ripe, fleshy, 1 article, 6–7 x 4–5 mm, ovoid.
Distribution and habitat: — Alyxia minimiflora is known from only one population, located on Pic aux chèvres peak, Dumbéa, near Nouméa. It is a rupicolous plant growing only on top of schistaceous cliffs, ca. 250 m elev. where another narrow-range species, Austrocallerya australis (Endl.) J.Compton & Schrire is also known.
Phenology:— From the few specimens available, A. minimiflora is known to flower between March and May. Fruits are only known from the type specimen, in May.
Etymology: —The species is the Alyxia with the shortest flowers in New Caledonia, thus justifying the epithet minimiflora.
Notes:— MacKee & Suprin 45389 and Veillon 7334 were included in A. tisserantii by Middleton (2002) and not yet gathered when Boiteau (1981) published the flora. They however show perfect matching with the type specimen and were collected in the same locality. As circumscribed here, A. tisserantii has much longer flowers (ca. 3 mm vs 1.5 mm in A. minimiflora), a longer inflorescence axis (ca. 5 mm vs 0–1.7 mm in A. minimiflora), and wider leaves (variable 5.5–12 mm vs remarkably stable 1.4–2 mm in A. minimiflora). Finally, the whole A. tisserantii plant is glabrous while A. minimiflora is densely pubescent, at least on young shoots.
Specimens examined:— NEW CALEDONIA: South province: Pic aux chèvres, elev. 250 m, 22°11'38"S, 166°27'37"E, 5 May 2022, Lannuzel, Foord & Pouget. 632 (NOU108942!); Pic aux chèvres, elev. 250 m, 22°11'38"S, 166°27'37"E, 5 May 2022, Lannuzel, Foord & Pouget 633 (NOU108943!; P01139656!); Koutio: Pic aux Chèvres, elev. 250 m, 11 March 1991, MacKee & Suprin 45389 (P04225605!!, L.2702438!); Dumbéa: sommet Pic aux chèvres, elev. 289 m, 11 March 1991, Veillon 7334 (NOU058309!, P04220397!).
description: Published as part of 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, pp. 1-43 in Phytotaxa 649 (1) on pages 16-18, DOI: 10.11646/phytotaxa.649.1.1, http://zenodo.org/record/13215783