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IAWA Bulletin n.s., Vol. 9 (2),1988,103-182

WOOD ANATOMY OF THE

by

Pieter Baas*, Petra M. Esser*, Marijke E. T. van der Westen*, and Marinus Zandee**

Contents

Summary ...... 104 Introduction ...... 104 Materials and methods ...... 106 Phenetic analysis ...... 106 Cladistic analysis ...... 106 Survey of wood anatomical character states in the Oleaceae ...... 107 Introduction 107 - Growth rings 108 - Vessel grouping and distribution 108 Vessel frequency and element size 110 - Vessel perforations 110 - Vessel wall pit- ting 111- Vessel wall thickness and sculpturing 112 - Tyloses and vessel contents 112 - Vascular tracheids 113 - Fibres 113 - Axial parenchyma 127 - Ray tissue 128 - Crystals 129 Generic wood anatomical descriptions ...... 129 Explanatory note 129 - Abeliophyllwn 129 - (including Linociera) 130 Comoranthus 132- 133- 134- 135- 135 - 137 - 137 - Jasminum 138 - Ligustrum 140 141- 142 - 142 - 143 - 143 145 - 146 - 149 - 151 - 152 153 - 153 - Tessarandra 155 Classification of the Oleaceae ...... 156 Phenetic wood anatomical classification ...... 156 Phylogenetic classification ...... 159 The position of Nyctanthes ...... 166 The wider affinities of the Oleaceae ...... 167 Ecological and functional considerations...... 168 A tentative evolutionary scenario for the Oleaceae ...... 173 Needs for further studies ...... 174 Keys to the woods of the Oleaceae ...... 174 Comprehensive wood anatomical key to the genera of the Oleaceae ...... 175 Simplified wood anatomical key to the genera of the Oleaceae...... 176 Acknowledgements ...... 177 References ...... 177

* Rijksherbarium, P.O. Box 9514, 2300 RA Leiden, The Netherlands. ** Institute of Theoretical Biology, Groenhovenstraat 5, 2311 BT Leiden, The Netherlands. 104 IAWA Bulletin n.s., Vol. 9 (2), 1988

Summary The wood anatomy of all 24 genera of the A tentative evolutionary scenario based on nearly eosmopolitan of the Oleaeeae is the analysis of ecological trends in extant deseribed on the basis of a study of 137 spe­ 01eaceae and the most parsimonious clado­ eies (c. 300 sampIes). The wood anatomical gram is provided. Two dichotomous identifi­ diversity has been used for a phenetic as weIl cation keys to the woods of the Oleaceae are as a phylogenetic classification. Important given. Most individual generic descriptions common elements of those classifications are: are followed by taxonomie and/or wood ana­ heterogeneity and likely unnatural status of tomical notes. the genera Olea and Chionanthus s.l. (in­ Key words: Phylogenetic classification, phe­ cluding Linociera) as conceived by eurrent netic classification, ecological and func­ taxonomic delimitation; support for the rec­ tional wood anatomy, xylem evolution, ognition of the subfamily Oleoideae (includ­ wood identification. ing Schrebera and Comoranthus, but exclud­ ing Myxopyrum) as a natural group; and in­ Introduction clusionofthe genusNyctanthes in an isolated The Oleaceae constitute a nearly eosmo­ position in the Oleaceae. In the phenetic clas­ politan family of , , and more sification 6 partly overlapping groups are rarely climbers. Many of its members are of recognised: I. all genera traditionally plaeed economic interest as ornamental species (F or­ in the Jasminoideae plus Myxopyrum and sythia, Jasminum, Ligustrum, Osmanthus, Syringa p.p.; 11. Ligustrum and Syringa p.p.; Syringa, and others), for their timber (e.g. III. Comoranthus and Schrebera; IV. Chio­ species of Chionanthus, Fraxinus, Olea), or nanthus p.p. (= Linociera), Forestiera, Frax­ their (Olea). The great diversity of inus, Haenianthus, Hesperelaea, Noronhia, wood structure within the family has been Olea p.p., Tessarandra; V. Chionanthus s.s. recognised since the early days of com­ (temperate species), Nestegis, Notelaea, Os­ parative wood anatomy by Sanio (1863), manthus, Olea p.p., Phillyrea, and Picconia; Müller (1876), and Kohl (1881) and has VI. Nyctanthes. Groups 11, III, IV and V since been summarised by Solereder (1899, eonstitute most of the Oleoideae in reeent and 1908) and Metealfe and Chalk (1950). tradition al systems of classification. In the Kohl' s thesis (1881), and to a lesser extent cladistic analysis these four groups form to­ the combined wood anatomical and cytolog­ gether a monophyletic group, supported by ieal study by Sax and Abbe (1932) are the an allopolyploid karyotype, and the presence only monographie wood anatomical surveys of flavone glyeosides. The subfamily Jasmi­ for the family to date, and these publications noideae is not supported by shared apo­ deal with apart of the genera only. Kohl's morphic anatomical, karyological or flavon­ taxonomie eonclusions are eompletely at odds oid character stateS. with those proposed in the present study. Ecological trends in the wood anatomy of This is probably because of his use of a clas­ the family include weak dependencies on sification and terminology of wood anatomi­ latitude and moisture availability of quanti­ cal elements which has since been found tative characters such as vessel diameter, deficient, as ~lready indicated by Solereder vessel frequency, and vessel member and (1885), and because of the limited knowledge fibre length in agreement with general trends of the systematic and diagnostic value of established in other woody groups. certain wood characters at his time. Fibre-tracheids, spiral thiekenings, and the A renewed wood anatomical survey of character syndrome of oblique to dendritic the Oleaceae is in tocontribute to the un­ vessel distribution with associated vascular derstanding of intergeneric affinities, which tracheids and large intervessel pits, are main­ eontinues to be the subject of discussion ly restricted to extratropical Oleaceae. Three (cf. Bentham & Hooker 1876; Harborne & alternative strategies are hypothesised for op­ Greene 1980; Johnson 1957; Kiew 1983, timal safety and efficiency of the hydraulic 1984; Kiew & Baas 1984; Knoblauch 1895; architecture of the Oleaceae. Piechura & Fairbrothers 1983; Sax & Abbe