Geissois

Abstract: This contribution presents additional, heretofore unreported observations on stipular structure, ontogeny, and nodal vascularization among taxa of the Cunoniaceae and presumed allies that deviate from the more common stipular condition described above. The taxa described are Aphanopetalum, Bauera, Brunellia, Davidsonia, Geissois, Gillbeea adenopetala, and Pseudoweinmannia

Abstract: Comparison of the four species groups comprising the tribe Geissoieae (Lamanonia in South America, Geissois sensu stricto from islands in the south-western Pacific, and Pseudoweinmannia and Geissois in Australia) showed differences in the stipules, inflorescences and flowers Molecular phylogenetic analyses suggested that Geissois sensu lato is paraphyletic, with Australian Geissois being closer to Pseudoweinmannia than to New Caledonian Geissois The name Karrabina is published to accommodate the Australian species formerly placed in Geissois, namely K benthamiana Rozefelds & HCHopkins and K biagiana Rozefelds & HCHopkins Distinguishing characters for Karrabina are: four lateral stipules per node that vary from free to largely fused between and sometimes across the petioles; inflorescences with a variable number of metamers and racemes, with both median and lateral modules that always lack a median raceme; and pale flowers with five or six calyx lobes and shortly exserted stamens Geissois ss differs in having: two intrapetiolar stipules per node; inflorescences consisting of few metamers and few racemes, with the modules being always lateral and possessing a median raceme; flowers with four red calyx lobes and prominently exserted stamens The generic limits of Lamanonia and Pseudoweinmannia remain unchanged

Abstract: Cunoniaceae are represented in New Caledonia by some 90 species, all of them endemic, and the family is thus a significant element in this diverse island flora. We present a descriptive survey of floral biology for the seven genera present, covering floral structure and colour, inflorescence shape, sexual system and phenology, plus details of floral visitors, where known, based on field observations; individual records of potential pollinators are tabulated in appendices. The flowers are polysymmetric (or almost so) and provide nectar and/or pollen as floral rewards. Two genera are dioecious and some species are mass flowering. Generalist entomophily is associated with several floral syndromes although the introduction of Apis mellifera has partially obscured historic relationships between some Cunoniaceae and their insect-pollinators. Codia and Pancheria both have sweetly scented, often creamish, spherical capitula and their floral visitors include honey bees, beetles, flies and native bees, especially halictids. Spiraeanthemum and Hooglandia have small, often whitish flowers in paniculate inflorescences but data on potential pollinators are few. Racemes occur in Weinmannia (flowers white, apparently scentless) and Cunonia p.p. (flowers white, pink or reddish with a faint foetid odour); visitors are mostly honey bees, plus ants, butterflies and native bees, and occasionally birds in the case of two reddish-flowered species. Ornithophily occurs in Geissois (flowers red, scentless, in bottle-brush racemes) and Cunonia macrophylla (flowers yellow-green, in one-sided racemes); their floral visitors are commonly Meliphagidae plus some Psittacidae and Zosteropidae. Pteropodid bats are also occasional visitors to Geissois. Geckos have been reported as flower-visitors in two genera though their contribution to pollen transfer is likely to be sporadic at most. Topics that require further investigation include some details of floral biology and the floral cycle, and the possible adaptive significance of different inflorescence shapes. Unanswered questions include: What visits taxa with paniculate inflorescences?, and for all genera: Which types of floral visitor are the most efficient pollinators? For the family as a whole, generalist entomophily appears to be the ancestral mode of pollen transfer and morphological specialisations to ornithophily have occurred independently in two groups of species and possibly in a third. Our data on birds and geckos agree with a known trend for these types of floral visitation and pollination to be well developed on islands, and flower-visiting by lizards in New Caledonia is likely to be more common than has been documented so far, both in Cunoniaceae and in the flora as a whole.

Abstract: A description, illustration, distribution map and conservation assessment are given for each of three new species of Cunoniaceae from New Caledonia and plants endemic to the same localities from other genera are mentioned. Cunonia bopopensis Pillon & H. C. Hopkins is known from forest on ultramafic soils at high elevation on Mt Tchingou. This massif offers ecological conditions markedly different from those of its surroundings, which may explain the occurrence of several micro-endemics on this mountain. Some specimens of C. bopopensis were previously identified as C. bernieri Guillaumin but the type of the latter is probably a hybrid and this name is now considered doubtful. Geissois belema Pillon & H. C. Hopkins is endemic to Ile Art in the Belep archipelago, where it occurs in forest on ultramafic soils; it is the only species of Geissois known from Ile Art. Pancheria xaragurensis H. C. Hopkins & Pillon is found largely on the little-explored Forgotten Coast (“Cote Oubliee”) of south-eastern Grande Terre, generally in maquis along streams and in river beds at low elevation on ultramafic substrate. Morphological and ecological variation in the widespread taxa Geissois pruinosa Brongn. & Gris and Weinmannia dichotoma Brongn. & Gris are discussed and the combinations G. pruinosa var. intermedia (Vieill. ex Pamp.) H. C. Hopkins & Pillon and W. dichotoma var. monticola (Daniker) H. C. Hopkins & Pillon are published to accommodate some of this variability.