Angiosperms: Unit 5, Chapter 31
Angiosperms success - flower and fruit
- Flower - modified leaves (sporophylls) around central receptacle
- Perianth - sepals and petals
- Sepals: base of attachment of flower to plant - enclose unopened floral bud
- Petales: inside whorl of sepals - attract pollinators
- Gynoecium: female part of the flower - one or more carpels
- Multiple carpls = pistil
- Stigma: pollen receptacle
- Style: connecting structure (neck) pollen tube will grow
- overy : house ovule
- androecium : male part of the flower
- Stamen (multiple in androecium) - stalk filament and anther pollen sac
Angiosperm reproduction
- Life cycle of an angiosperm
- Double fertilization: zygote 1st endosperm 2nd
- Embryo has radicle (small root) and cotyledons (leaf like organ)
- Fruits
- Ovary wall thicken after fertilization
- Can be fleshy or dry
- Not all fruits from single ovary
- Aid in dispersal
Diversity of angiosperms
- Anthophyta - single phylum of angiosperms
- Basal angiosperms - magnoliidae
- Magnolias laurels peppers
- Laurels: avocado cinnamon spicebush
- Monocots: single cotyledon
- Vascular tissue scattered, ring in roots
- No tap root
- Lilies orchids grasses
- Dicots - two cotyledons, flowers in multiples of 4 or 5
- Herbaceous or woody
- Main tap root
- ⅔ of all flowering plants