Evolutionary tendencies in African Marantaceae - evidence from floral morphology, ecology and phylogeny Dissertation zur Erlangung des Grades „Doktor der Naturwissenschaften“ am Fachbereich Biologie der Johannes Gutenberg-Universität Mainz Alexandra Ley geb. in Bonn - Bad Godesberg Mainz, 2008 Meinen Eltern gewidmet View on the river Ivindo from the biological station “Ipassa”, 13 km east of Makokou, Gabon (2006) We travel together, passengers on a little space ship, dependent Upon its vulnerable reserves of air and soil – all committed For our safety to its security and peace, and preserved From annihilation only by the care, the work, and, I will say, the love, we give our fragile craft. Adlai Stevenson Tag der mündlichen Prüfung: 10. Juli 2008 CONTENTS __________________________________________________________________________________________________________ ______________________________________________________________________________________________ __________________________ CONTENTS SUMMARY OF THE THESIS .................................................................................... 1 ZUSAMMENFASSUNG .............................................................................................. 4 1 GENERAL INTRODUCTION ............................................................................. 7 2 FIELD INVESTIGATIONS IN AFRICAN MARANTACEAE: PLANT ARCHITECTURE, PLANT-ANIMAL INTERACTIONS, BREEDING SYSTEMS AND FRUIT-SET .............................................................................. 13 2.1 ABSTRACT ................................................................................................................. 13 2.2 INTRODUCTION ......................................................................................................... 14 2.3 MATERIAL AND METHODS .................................................................................... 16 2.3.1 RESEARCH SITE ................................................................................................... 16 2.3.2 PLANT MATERIAL .............................................................................................. 17 2.3.3 PHENOLOGICAL SEASONALITY ..................................................................... 19 2.3.4 FLOWERING SEQUENCE ................................................................................... 19 2.3.5 MORPHOMETRIC MEASUREMENTS ............................................................... 19 2.3.6 NECTAR ................................................................................................................. 20 2.3.7 POLLEN .................................................................................................................. 20 2.3.8 POLLINATORS AND FLOWER VISITORS ....................................................... 21 2.3.9 POLLINATION EXPERIMENTS .......................................................................... 22 2.3.10 FRUIT DEVELOPMENT, SEED SET AND INSECT FEEDING ...................... 22 2.4 RESULTS ..................................................................................................................... 24 2.4.1 ARCHITECTURE, INFLORESCENCES AND PHENOLOGY ........................... 24 2.4.2 FLORAL DIVERSITY AND ATTRACTANTS .................................................... 32 2.4.2.1 Floral diversity ............................................................................................... 32 2.4.2.2 Nectar reward .............................................................................................. 33 2.4.2.3 Pollen load ..................................................................................................... 34 2.4.3 PLANT ANIMAL INTERACTION ....................................................................... 35 2.4.3.1 Bees ............................................................................................................... 38 2.4.3.2 Sunbirds ......................................................................................................... 43 2.4.3.3 Pollinator visitation rate ............................................................................... 45 2.4.3.4 Nectar robbers .............................................................................................. 45 2.4.3.5 Ants ................................................................................................................. 45 2.4.3.6 Beetles ........................................................................................................... 46 2.4.4 BREEDING SYSTEMS AND FRUIT-SET ........................................................... 46 2.4.4.1 Breeding system ........................................................................................... 46 2.4.4.2 Fruit-set .......................................................................................................... 46 2.4.4.3 Fruits and seeds ........................................................................................... 47 2.4.4.4 Vegetative reproduction .............................................................................. 50 2.5 DISCUSSION .............................................................................................................. 62 2.5.1 FLOWER TYPES AND POLLINATION SYNDROMES .................................... 62 2.5.1.1 Bee-pollination-syndrome ........................................................................... 62 2.5.1.2 Bird-pollination-syndrome ........................................................................... 64 2.5.1.3 Specialization to pollinator guilds ............................................................... 65 2.5.2 BREEDING SYSTEM ............................................................................................ 66 2.5.2.1 Geitonogamy versus xenogamy ................................................................ 66 CONTENTS __________________________________________________________________________________________________________ ______________________________________________________________________________________________ __________________________ 2.5.2.2 Autogamy ....................................................................................................... 68 2.5.3 PHENOLOGY AND POLLINATOR SHARING .................................................. 68 2.5.4 FRUITSET AND VEGETATIVE VIGOUR .......................................................... 70 2.5.5 DISPERSAL ............................................................................................................ 71 2.5.5.1 Water .............................................................................................................. 71 2.5.5.2 Mammals ....................................................................................................... 72 2.5.5.3 Birds ............................................................................................................... 73 2.6 CONCLUSIONS .......................................................................................................... 73 3 DIVERSITY IN FLORAL SYNORGANIZATION AFFECTS POLLENDEPOSITION AND BREEDING SYSTEM IN MARANTACEAE 74 3.1 ABSTRACT ................................................................................................................. 74 3.2 INTRODUCTION ......................................................................................................... 74 3.3 MATERIAL AND METHODS .................................................................................... 78 3.4 RESULTS ..................................................................................................................... 80 3.4.1 GENERAL PRINCIPLES OF FLORAL CONSTRUCTION IN MARANTACEAE ................................................................................................. 80 3.4.2 SPECIFIC TRAITS IN THE SARCOPHRYNIUM CLADE ................................... 91 3.4.2.1 Hypselodelphys and Trachyphrynium ...................................................... 91 3.4.2.2 Megaphrynium and Thaumatococcus ....................................................... 92 3.4.2.3 Sarcophrynium .............................................................................................. 93 3.4.3 SPECIFIC TRAITS IN THE CALATHEA CLADE ................................................ 95 3.4.3.1 Haumania ...................................................................................................... 95 3.4.3.2 Calathea, Pleiostachya and Ischnosiphon ............................................... 96 3.4.4 SPECIFIC TRAITS IN THE DONAX CLADE ...................................................... 99 3.4.4.1 Thalia .............................................................................................................. 99 3.4.4.2 Donax, Schumannianthus and Phrynium ............................................... 100 3.4.5 SPECIFIC TRAITS IN THE MARANTA CLADE ............................................... 101 3.4.5.1 Maranta ....................................................................................................... 102 3.4.5.2 Hylaeanthe hoffmannii ............................................................................... 102 3.4.5.3 Ctenanthe, Myrosma and Stromanthe .................................................... 103 3.4.5.4 Halopegia ................................................................................................... 104 3.4.6 SPECIFIC TRAITS IN THE STACHYPHRYNIUM CLADE ............................... 107 3.4.6.1 Afrocalathea ...............................................................................................