A New Species of Zygogynum (Winteraceae) from New Caledonia

Abstract

SUMMARYZygogynum fraterculum, a new species of Zygogynum is described and illustrated.Key words: Winteraceae, Zygogynum, New Caledonia. Treelet 3-8 m high. Branchlets rather slender; dry epidermis blackish brown, longi tudinally wrinkled, cells laterally distinct, almost flat. Cataphylls (strongly reduced leaves), but usually their scars, between and below the leaves. Leaves scattered. Petioles 0.5-1.1 cm long, flat or proximally slightly canaliculate above, rounded to triangular below. Blade narrowly obovate, 1.8-5.6 by 0.6-1.7 cm, thinly coriaceous; apex broadly rounded, rarely obtuse; base attenuate; in sicco margins recurved; midrib flat above, slightly raised to prominent and rounded to triangular below; nerves at the middle of the blade at an angle of 55-65º(-80º) to the midrib, faint to prominulous above, faint to inconspicuous below. On lower leaf surface only stomata grey. Inflorescences with 0(-6) bract scars below lowest partial inflorescence; partial inflorescences 1-3, 1 flow ered. Only scars of bracts seen. Pedicels flattened, often apically somewhat broadened, 35 -55 mm long, smooth. Calyx ruptured irregularly into 2 or 3(-5) lobes, rather thick to rather thin, patent, 3-4 mm long. Corolla: 4 or 5 outer petals for 0.5-0.8 of their length connate into a continuous ring which upon anthesis ruptures along slightly thinner areas demarcating the petals into ovate lobes 10-15 by 4-9 mm; inner petals 8-11, free, elliptic to obovate, towards stamens decreasing in size, innermost ones 5.5 by 3 mm. All petals especially on adaxial side micropapillate by high convex cells; brachysclereids not seen. Stamens 59-81, 3-5 mm long, distal stamens longer than proximal ones; filaments obovoid to rod-shaped, (partly) micropapillate by high-convex cells; thecae apical, at the median touching but distinctly demarcated, at 40-120º to each other. Pollen in tetrads; exine reticulate. Carpels 10-14, free, 3-3.5 by 2.5-3.5 by 1.5-2 mm; apex long, straight to convex; stigma rather broad, abaxially as long as to slightly longer than carpel apex, adaxially after a sharp angle descending over Zygogynum fraterculum

Pollen morphology of extant Winteraceae: a study allowing SEM-based affiliation of its fossil representatives

“…The only way to properly compare and/or affiliate fossil Winteraceae pollen/tetrads to extant taxa is by using combined data obtained from LM and SEM, especially from high-resolution SEM studies. Here we provide combined LM and SEM analyses of 35 samples of Winteraceae, representing seven of the eight genera and 20 of the approximately 65 species currently accepted by Vink (1970Vink ( -2003. The pollen/tetrads are studied by both LM and SEM, and diagnostic features observed under high-resolution SEM are noted.…”

“…At present, Winteraceae comprise about 65 species in four to eight genera (e.g. Vink 1993), with the greatest generic and species diversity in Australasia (Belliolum, Bubbia, Exospermum, Pseudowintera, Tasmannia, Zygogynum;Vink 1970, 1985, 1988, 2003, Doust & Drinnan 2004 and America (Drimys;Smith 1943). A single taxon occurs in Madagascar (Takhtajania;Leroy 1978, 1980, Vink 1978.…”

Intercontinental long-distance dispersal of Canellaceae from the New to the Old World revealed by a nuclear single copy gene and chloroplast loci

“…s.I., which according to Vink (1985Vink ( , 1988, include Bubbia Tieghem and Exospermum Tieghem and was confirmed by Marquínez et al (2009). Winteraceae comprise about 80 species and again show a broad distribution in the southern hemisphere, including Australasia, Madagascar, Central and South America (Vink, 1988(Vink, , 2003. Based on divergence time estimates published by Marquínez et al (2009), the earliest cladogenesis of Winteraceae predated the fragmentation of Gondwana and thus it was hypothesized that Winteraceae's extant distribution was explained by continental vicariance.…”

Deux Nouvelles Espèces du Massif du Panié (Nouvelle-Calédonie): Meryta Rivularis Lowry (Araliaceae) et Pandanus Taluucensis Callm. (Pandanaceae)

“…Ce massif a été de nombreuses fois prospecté par les botanistes, notamment par le sentier de sa pente Est, emprunté par presque tout ceux qui visitent le site. Plus récemment, des récoltes ont été faites sur la face ouest, révélant immédiatement des nouveautés telles que Zygogynum fraterculum Vink (VINK, 2003). Malgré de nombreuses récoltes, la connaissance de la flore du massif dans son ensemble, reste très incomplète.…”