Alyxia urceolata Lannuzel

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 : 33-35

Alyxia urceolata Lannuzel , sp.nov. ( Figs. 19 , 20 ), (urn:lsid:ipni.org:names:77336420-1)

Diagnosis:— Alyxia urceolata is a small dense shrub characterized by its small linear leaves, and the urceolate shape of its small flowers. It is similar to A. caletioides when sterile but still differs by its narrower leaves (0.15–0.25 cm vs 0.15–0.45 cm in A. caletioides ). When fertile, it is readily distinguishable by its smaller and axillary flowers. It is also similar to A. minimiflora and A. rosmarinifolia but differs from the former by longer flowers and from the second by the young parts’ pubescence.

Type:— NEW CALEDONIA, Mont Boulinda , elev. 1100 m, 5 September 1971, Schmid 4031, holotype: NOU [ NOU022042 !] ; isotype: P [P05391605!]

Small shrub, up to 50 cm, young stems puberulent; latex white. Leaves ternate, subcoriaceous, green adaxially, light green abaxially when young, slightly revolutate, petiole 1–2.5 mm long, puberulent, lamina linear, 9.5–13.5 × 1.5–2.5 mm; base cuneate, apex rounded, mucronate, both surfaces looking lustrous but tomentulose and covered with very short hairs (ca. 0.01 mm long) on main veins abaxially, leaf venation not visible apart from the midrib. Flowers mostly axillary, sometimes subterminal, solitary and sometimes grouped in fascicules, axes green, pubescent, null to 2 mm, pedicels not visible, covered by 3–7 bracts, ca. 1 × 1 mm, blackish, pubescent.

Flower 5-merous, narrowly urceolate, 5.5 × 1.5 mm. Calyx lobes appressed to corolla, lanceolate, acute at apex, 2 mm long, green to blackish, pubescent, 5. Corolla tube yellowish, lobes white, tube ca. 3 × 1.5 mm, glabrous outside, with 2 rings of hairs inside, first around stigma, composed of 0.1mm long erected hairs, second around anthers, composed of 0.2 mm erected hairs, lobes sinistrorse, rounded, glabrous with some hairs at base outside, spreading, ca. 1 mm long.

Anther cone 0.8 mm long, not exserted; filaments 0.2 mm long, inserted at 2/3 of tube length. Ovary densely pubescent with 0.1 mm long hairs, style 0.8 mm long, glabrous, stigma ovoid, acute, hairy at top. Fruit black, fleshy, 1–2 article, 4–7 × 4–5 mm, globose to ovoid.

Distribution and habitat: — Alyxia urceolata is distributed on ultramafic massifs, in the northwestern part of Grande Terre, New Caledonia, from Mont Boulinda to Mont Ouazangou. It grows in open shrublands, from 500 to 1100 m elev., on ultramafic substrate.

Phenology:— From herbarium specimens and pictures available, the species may be able to flower all year round. Fruits were collected in January, July, and September.

Etymology:— The species is named after the urceolate shape of the corolla tube.

Notes: —Specimens of this new species were included in Alyxia caletioides by previous authors ( Boiteau 1981 and Middleton 2002), but differs from it by its shorter and axillary flowers. On sterile specimens, this species is distinct by its narrower, strictly linear leaves, and the more regular phyllotaxy.

Specimens examined: — Koniambo, elev. 700 m, 22 February1972, Jaffré 695 ( NOU021991 !; P05391638!) ; Massif du Koniambo, elev. 520 m, 1 June 1972, Jaffré 767 ( NOU022045 !) ; Massif du Boulinda, elev. 800 m, 1 July 1972, Jaffré 827 ( NOU021992 !) ; Koniambo, elev. 850 m, 22 November 2002, Jaffré 3536 ( NOU021997 !) ; Mt Ouazangou , proche du sommet, elev. 850 m, 3 July 2018, Lannuzel 178 ( NOU090306 !) ; Mt Ouazangou , elev. 844 m, 20°44’34’S, 164°29’42’’E, 7 March 2019, Lannuzel 246 ( NOU107093 !) ; Mt Ouazangou , elev. 840 m, 20°44’32’S, 164°29’43’’E, 7 March 2019, Lannuzel 249 ( NOU107095 !) ; Mt Boulinda , elev. 1100 m, 5 September 1971, Schmid 4031 ( NOU022042 !) ; Mont Boulinda, elev. 700–800 m, 22 April 1968, Veillon 1757 ( NOU058244 !; P04260811!) .

Figures

FIGURE 19. Alyxia urceolata with detail of a mature fruit (A), flower (B), habit (C) and a flowering branch (D). Photographer: G. Lannuzel from Lannuzel 178.

FIGURE 20.Known distribution of Alyxia urceolata (dots). Symbols with “T” represent type specimens.Grayed areas represent ultramafic substrates.