A search for phylogenetically informative wood characters in the subfamily Rauvolfioideae (Apocynaceae)

Frederic Lens 1 , Mary E. Endress 2 , Pieter Baas 3, Steven Jansen 4 and Erik Smets 1,3 1 Laboratory of Plant Systematics, K.U.Leuven, Belgium; 2 Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, 8008 Zürich, Switzerland; 3 Nationaal Herbarium Nederland, Leiden branch, The Netherlands ; 4 Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, United Kingdom

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

Plumeria rubra Catharanthus roseus Vinca minor

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Stemmadenia littoralis Allamanda schottii Carissa macrocarpa Cascabela thevetia

Simões et al. 2007: 5 chloroplast genes + morphology

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climbing taxa

Rauvolfioideae paraphyletic APSA clade: A pocynoideae P eriplocoideae S ecamonoideae A sclepiadoideae

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

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Vessel grouping

CONCLUSION

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Vessel perforations, vessel pitting

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Imperforate tracheary elements

CONCLUSION

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Axial parenchyma distribution

CONCLUSION

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Rays

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Calcium oxalate crystals

CONCLUSION

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Laticifers and intraxylary phloem

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Diagnostic wood features within Tabernaemontaneae s.s. …

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

… lead to recognition of the former tribe Ambelanieae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Climbing vs. nonclimbing genera in Willughbeieae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION CONCLUSION

Climbing vs. nonclimbing genera in Willughbeieae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Vessel element length: — > 700 µm — 400-700 µm — < 400 µm

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climbing taxa

CONCLUSION

Aspidospermeae Alstonieae Kopsia-Vinceae Vinceae

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Cli-Willughbeieae Noncli-Willughbeieae Ambelanieae (Tabern s.l.) Tabernaemontaneae s.s.

Diplorhynchus

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Melodineae

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Alyxieae Hunterieae Plumerieae Carisseae Wright.,

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Nerieae, Malouet.

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Periplocoideae

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Remaining Apocynoideae

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Secamonoideae

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Asclepiadoideae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Vessel grouping: — solitary vessels — radial multiples — clusters common

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climbing taxa

CONCLUSION

Aspidospermeae Alstonieae Kopsia-Vinceae Vinceae



Cli-Willughbeieae Noncli-Willughbeieae Ambelanieae (Tabern s.l.) Tabernaemontaneae s.s.

Diplorhynchus



Melodineae



Alyxieae Hunterieae Plumerieae Carisseae Wright.,



Nerieae, Malouet.



Periplocoideae



Remaining Apocynoideae

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Secamonoideae



Asclepiadoideae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

Axial parenchyma: — excl apotracheal — apo- & paratracheal — excl paratracheal — absent



climbing taxa

CONCLUSION

Aspidospermeae Alstonieae Kopsia-Vinceae Vinceae



Cli-Willughbeieae Noncli-Willughbeieae Ambelanieae (Tabern s.l.) Tabernaemontaneae s.s.

Diplorhynchus



Melodineae



Alyxieae Hunterieae Plumerieae Carisseae Wright.,



Nerieae, Malouet.



Periplocoideae



Remaining Apocynoideae



Secamonoideae



Asclepiadoideae

INTRODUCTION OBJECTIVES RESULTS DISCUSSION

No cells per axial parenchyma strand: — 8-10 — 4-8 — < 4



climbing taxa

CONCLUSION

Aspidospermeae Alstonieae Kopsia-Vinceae Vinceae



Cli-Willughbeieae Noncli-Willughbeieae Ambelanieae (Tabern s.l.) Tabernaemontaneae s.s.

Diplorhynchus



Melodineae



Alyxieae Hunterieae Plumerieae Carisseae Wright.,



Nerieae, Malouet.



Periplocoideae



Remaining Apocynoideae



Secamonoideae



Asclepiadoideae

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