31 research outputs found

    Macrophotographic wood atlas of Annonaceae.

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    In this article, a general description of the microscopic wood anatomy of Annonaceae is given. We provide a description of the wood anatomical features of the family and of all subfamilies and tribes, all from material in the Utrecht Wood collection. Hand-lens images can be an important help in identification, not only at the family level, but also at the level of genera or below, notwithstanding the fact that the number of characters that can be easily observed in end-grain photographs is restricted. The differences are often slight and difficult to summarize in a few words, making illustrations an indispensable tool. Therefore, we provide end-grain photographs of cross-sections of wood of 66 genera and > 90 species of Annonaceae. The variation seen in lens key characters is discussed against the framework of the current phylogenetic tree of the family. Additional remarks on microscopic features are given when appropriat

    Wood anatomical classification using iterative character weighing

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    In this paper we investigate the pattern of wood anatomical variation in some groups of Rubiaceae (i.e. Cinchoneae, Rondeletieae and Condamineae) by using a numerical pattern detection method which involves character weighing (Hogeweg 1975). In this method character weights are obtained iteratively on the basis of the distribution of character values in previously generated classes; these classes being generated by agglomerative cluster analysis, initially with characters weighed equally and subsequently with characters weighed differentially as indicated above. The result of such a study consists of a sequence of dendrograms together with the character weights by which these are produced. Our biological conclusions include: The so obtained results confirm the conclusions drawn by Koek-Noorman & Hogeweg (1974) that the pattern of variation in the wood anatomical structure of these taxa is consistent with the existing classifications at the genus level but does not warrant the higher level classification in Cinchoneae, Rondeletieae and Condamineae as each of these groups show two majorly different woodtypes (differing most conspicuously with respect to libriform fibres and fibre tracheids) while these wood types constitute the major pattern of variation in the sample. However, during the iteration, the Rondeletieae and Cinchoneae tend to be distinguished as separate groups on a level below this main bipartition. The Condamineae remain scattered. The genus Cinchona becomes sharply separated from the other groups during the iteration. Its intermediate position with respect to fibre tracheids and libriform fibres was noted prior to this analysis by Koek-Noorman (Koek-Noorman & Hogeweg 1974). Rather surprisingly, ambiguities (in the sense of being differently classified by different authors) in the existing classifications based mainly on flower morphology reoccur in our iteration based on wood anatomical data in the sense that these taxa change position in the later steps of the iteration. Finally we note that character weights obtained by our method do not spoil the grouping in genera as did character weights obtained by considering the literature on evolutionary trends in wood anatomy (Koek-Noorman & Hogeweg 1974), and that the character weights obtained by our method are not counter to intuition

    Opiliaceae

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    Studies in Annonaceae XXXVI. The Duguetia Alliance: Where the Ways Part

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    Volume: 87Start Page: 234End Page: 24

    Systematic wood anatomy of the tribe Guettardeae (Rubiaceae)

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    Systematic wood anatomy of the tribe Guettardeae (Rubiaceae). The wood anatomy of nearly all genera of the Guettardeae (Rubiaceae, Guettardoideae) has been examined, and in this respect the tribe is heterogeneous. Suggestions are made for a delimitation of the tribe. Guettarda, Bobea, Antirhea, Malanea and Chomelia Jacq. are sufficiently similar in their wood anatomical characters to warrant retention in the same tribe. Machaonia, Timonius and Dichilanthe are anomalous. Suggestions are given for taxonomic revisions of some genera based on their wood anatomy

    Byrsonima arthropoda

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    Angiosperm
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