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Specimens from Southern Chile belonging to two undescribed aphid species held at the Natural History Museum in London have been studied. Aphis luzuriagae sp. n. collected on Luzuriaga radicans and on other unidentified Luzuriaga species (Alstroemeriaceae) is described from apterous and alate viviparous females. Aphis gaultheriae sp. n. collected on Gaultheria mucronata (Ericaceae) is described from apterous viviparous females. Taxonomic peculiarities of both species are discussed. [ABSTRACT FROM AUTHOR]

Background and Aims While the climbing habit allows vines to reach well-lit canopy areas with a minimum investment in support biomass, many of them have to survive under the dim understorey light during certain stages of their life cycle. But, if the growth/survival trade-off widely reported for trees hold for climbing plants, they cannot maximize both light-interception efficiency and shade avoidance (i.e. escaping from the understorey). The seven most important woody climbers occurring in a Chilean temperate evergreen rainforest were studied with the hypothesis that light-capture efficiency of climbers would be positively associated with their abundance in the understorey. Methods Species abundance in the understorey was quantified from their relative frequency and density in field plots, the light environment was quantified by hemispherical photography, the photosynthetic response to light was measured with portable gas-exchange analyser, and the whole shoot light-interception efficiency and carbon gain was estimated with the 3-D computer model Y-plant. Key Results Species differed in specific leaf area, leaf mass fraction, above ground leaf area ratio, light-interception efficiency and potential carbon gain. Abundance of species in the understorey was related to whole shoot features but not to leaf level features such as specific leaf area. Potential carbon gain was inversely related to light-interception efficiency. Mutual shading among leaves within a shoot was very low (<20 %). Conclusions The abundance of climbing plants in this southern rainforest understorey was directly related to their capacity to intercept light efficiently but not to their potential carbon gain. The most abundant climbers in this ecosystem match well with a shade-tolerance syndrome in contrast to the pioneer-like nature of climbers observed in tropical studies. The climbers studied seem to sacrifice high-light searching for coping with the dim understorey light. [ABSTRACT FROM AUTHOR]

Patterns of headspace volatiles and flavonoids extracts from flowers of sympatric populations of Luzuriaga radicans Ruiz et Pav. (Monocotyledoneae: Luzuriagaceae), L. polyphylla (Hook.) J.F.Macbr., and a Luzuriaga taxon which presented some morphological characters of one of the species and other characters of the other species, suggest that this latter taxon is a hybrid between the two accepted species. [ABSTRACT FROM AUTHOR]

The article presents a proposal for the rejection of the Luzuriaga cordata under Dioscoreaceae. It notes that L. Cordata has not been valid in botanical literature because of its overlooked characteristic classified under the family of Dioscoreaceae. It cites name reassessments which show that generic placement of Dioscorea and Epipetrum species are classified under paraphyletic Dioscorea, which is in contrast to the independent monophyletic genus interpreted by other taxonomist.