Saturday, May 27, 2017

[Botany • 2017] Acropogon mesophilus • A Rare and Threatened New Species (Malvaceae, Sterculioideae) from the Mesic Forest of New Caledonia [Novitates Neocaledonicae VI]

Acropogon mesophilus  Munzinger & Gâteblé


A new species, Acropogon mesophilus Munzinger & Gâteblé (Malvaceae, Sterculioideae), is described from New Caledonia. This species is endemic to non-ultramafic areas, along the southwestern coast of Grande-Terre. The species has large leaves, widely ovate to ovate, and entire, and might be confused with only two other endemic species, namely A. bullatus (Pancher & Sebert) Morat and A. veillonii Morat. However, A. mesophilus differs from the other two species most evidently by its leaves 3-nerved, flat, and with truncate to rounded bases, versus leaves 5-nerved, bullate, and with cordate bases. A line drawing and color photos are provided for the new species, along with a discussion of its morphological affinities and a preliminary risk of extinction assessment of Endangered.

Keywords: Acropogon, Malvaceae, mesic forest, New Caledonia, new species, Sterculioideae, taxonomy, threatened species, Eudicots

Acropogon mesophilus Munzinger & Gâteblé spec. nov.A. Overview of a single big tree. B. Flowering branch. C. Leaves. D. Inflorescence. E. Male (left) and female (right) flowers. 

Acropogon mesophilus Munzinger & Gâteblé, spec. nov. 

Type:— NEW CALEDONIA. Province Sud: Boulouparis, Camp Brun, le long de la Diahot, 130 m, 21°49’29.85”S, 165°54’50.71”E, 30 September 2015, Gâteblé 711 (holotype P-01069417!; isotypes G!, K!, MEL!, MPU-028533!, MO!, NOU-081994!, NOU-081995!, P-01069418!). 

Diagnosis:— Acropogon mesophilus Munzinger & Gâteblé differs from A. bullatus and A. veillonii by its flat, ovate leaf blade, with base truncate to rounded, three main palmate veins and many evident domatia, and by its yellow sepals with 2–4 grayish-purple stripes per calyx lobe.

Etymology:— The plant is named after the mesic forests where it grows.

FIGURE 2.— Acropogon mesophilus Munzinger & Gâteblé spec. nov. (A–F), A. bullatus (G) & A. veillonii (H):
A. Overview of a single big tree. B. Flowering branch. C. Leaves. D. Inflorescence. E. Male (left) and female (right) flowers. F. Follicles. G–H. Inflorescences.

Gâteblé 711 (A–B), Gâteblé et al. 685 (C), Gâteblé 719 (D), Le Borgne 58 (E–F), Gâteblé & Butaud 733 (G), photos by G. Gâteblé (A–D & G), T. Le Borgne (E–F) & J.-F. Butaud (H).   DOI:  10.11646/phytotaxa.307.3.2 

Jérôme Munzinger and Gildas Gâteblé. 2017. Novitates Neocaledonicae VI: Acropogon mesophilus (Malvaceae, Sterculioideae), A Rare and Threatened New Species from the Mesic Forest of New Caledonia. Phytotaxa. 307.3; 183-190. DOI:  10.11646/phytotaxa.307.3.2