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Continuing Trends in Plant Evolution. Ultimate reduction of water-dependent gametophyte double fertilization Vascular tissue – improved more Herbaceous habit Secondary compounds Flowers – more efficient pollen Fruits – seed dispersal. Green: all these are in sporophyte. Flowers & fruits.
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Continuing Trends in Plant Evolution • Ultimate reduction of water-dependent gametophyte • double fertilization • Vascular tissue – improved more • Herbaceous habit • Secondary compounds • Flowers – more efficient pollen • Fruits – seed dispersal Green: all these are in sporophyte
Flowers & fruits • Flowers attract & encourage pollinators • Fruits aid in dispersal of seeds
Flowers & fruits • Flower a major advancement • Flower parts are modified leaves • Sepals – protect flower in bud • Petals – attract pollinators • Stamens – produce pollen • Pistil(s) – produce and protect ovules • Fruit develops from ovary
Flower Pistil
Flowering plant life cycle Meiosis Pollen grain ♂ Sporophyte Seed dispersal & germination Meiosis Ovary Gametophytes Ovule ♀ Fertilization (double)
Evolution of flower & fruit • First fossils: late Jurassic period of Mesozoic era • Diversified during Cenozoic era • Coevolution with pollinators
Fruits Orchid
Flowering plants survey • “Angiosperms” (= covered seed) • Phylum Anthophyta • Magnolias – primitive • Monocots – grasses, palms, lilys, etc. • Eudicots – everything else
Monocots Oriental lily Grass family, Andropogon
Eudicot Pear Pyrus
Smallest flower Water Meal, Wolffia Largest flower Rafflesia and friends
What does this pollinate??? Large, hairy bee fly from Stehekin