1Laboratory of Plant Systematics, K'U'Leuven, Belgium 2Institute of Systematic Botany, University of

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A search for phylogenetically informative wood
characters in the subfamily Rauvolfioideae
(Apocynaceae)
Frederic Lens1, Mary E. Endress2, Pieter Baas3,
Steven Jansen4 and Erik Smets1,3

• 1Laboratory of Plant Systematics, K.U.Leuven,
  Belgium 2Institute of Systematic Botany,
  University of Zurich, Zollikerstrasse 107, 8008
  Zürich, Switzerland 3Nationaal Herbarium
  Nederland, Leiden branch, The Netherlands
  4Jodrell Laboratory, Royal Botanic Gardens Kew,
  Richmond, Surrey TW9 3DS, United Kingdom

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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION

• Ca. 1000 spp., 84 genera, 10 tribes
• Small to medium-sized trees, tropical lowland
  forests
• Lianas in 24 genera, most diverse in
  Willughbeieae
• Uniform flower morphology
• Traditional classifications based on seed and
  fruit characters

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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Allamanda schottii
Stemmadenia littoralis
Carissa macrocarpa
Cascabela thevetia
4
Simões et al. 2007 5 chloroplast genes
morphology ? climbing taxa
APSA clade -Apocynoideae -Periplocoideae -Secamon
oideae -Asclepiadoideae
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION

• (1) Detailed wood anatomical descriptions
• LM and SEM observations
• 91 species, 50 genera, all 10 tribes
• CTFw, Lw, MADw, SJRw, Tw, WAGw
• (2) Find meaningful wood features characterizing
  Rauvolfioideae tribes
• (3) Compare anatomy of climbers vs. nonclimbers
• (4) Unravel wood evolution within Apocynaceae

6
INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Vessel grouping
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Vessel perforations, vessel pitting
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Imperforate tracheary elements
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Axial parenchyma distribution
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Rays
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Calcium oxalate crystals
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Laticifers and intraxylary phloem
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Diagnostic wood features within Tabernaemontaneae
s.s.
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
lead to recognition of the former tribe
Ambelanieae
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Climbing vs. nonclimbing genera in Willughbeieae
Climbers
Erect
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Climbing vs. nonclimbing genera in Willughbeieae
Climbers
Erect
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Aspidospermeae
Alstonieae
Vessel element length gt 700 µm 400-700 µm
lt 400 µm
Kopsia-Vinceae
Vinceae
Cli-Willughbeieae
?
Noncli-Willughbeieae
Ambelanieae (Tabern s.l.)
Tabernaemontaneae s.s.
Diplorhynchus
Melodineae
?
Alyxieae
?
Hunterieae
Plumerieae
Carisseae
? climbing taxa
Wright., ?Nerieae, Malouet.
Periplocoideae
?
Remaining Apocynoideae
?
Baileyan trend!
Secamonoideae
?
Asclepiadoideae
?
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Aspidospermeae
Vessel grouping solitary vessels radial
multiples clusters common
Alstonieae
Kopsia-Vinceae
Vinceae
Cli-Willughbeieae
?
Noncli-Willughbeieae
Ambelanieae (Tabern s.l.)
Tabernaemontaneae s.s.
Diplorhynchus
Melodineae
?
Alyxieae
?
Hunterieae
Plumerieae
Carisseae
? climbing taxa
Wright., ?Nerieae, Malouet.
Periplocoideae
?
Remaining Apocynoideae
?
Secamonoideae
?
Asclepiadoideae
?
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Aspidospermeae
Axial parenchyma excl apotracheal apo-
paratracheal excl paratracheal absent
Alstonieae
Kopsia-Vinceae
Vinceae
Cli-Willughbeieae
?
Noncli-Willughbeieae
Ambelanieae (Tabern s.l.)
Tabernaemontaneae s.s.
Diplorhynchus
Melodineae
?
Alyxieae
?
Hunterieae
Plumerieae
Carisseae
? climbing taxa
Wright., ?Nerieae, Malouet.
Periplocoideae
?
Remaining Apocynoideae
?
Secamonoideae
?
Asclepiadoideae
?
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION
Aspidospermeae
No cells per axial parenchyma strand 8-10
4-8 lt 4
Alstonieae
Kopsia-Vinceae
Vinceae
Cli-Willughbeieae
?
Noncli-Willughbeieae
Ambelanieae (Tabern s.l.)
Tabernaemontaneae s.s.
Diplorhynchus
Melodineae
?
Alyxieae
?
Hunterieae
Plumerieae
Carisseae
? climbing taxa
Wright., ?Nerieae, Malouet.
Periplocoideae
?
Remaining Apocynoideae
?
Secamonoideae
?
Asclepiadoideae
?
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INTRODUCTION OBJECTIVES RESULTS
DISCUSSION CONCLUSION

• Rauvolfioideae wood anatomically diverse
• Typical wood characters for most tribes
• Vessel grouping, vessel element length
• Number of cells per axial parenchyma strand
• Fibre type
• Climbing vs. nonclimbing anatomy
• Paratracheal vs. apotracheal parenchyma
• Tracheid presence vs. absence
• Some wood characters are diagnostic at the family
  level
• E.g. Baileyan trend for vessel element length

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