what are angiosperms?
flowering plants
when did angiosperms evolve?
bennettitales
225-56mya
Look like cycads but have flowers
Reproductive structures are condensed shoots of sterile bracts with highly modified male and female sporophylls—features similar to the highly condensed flowers of angiosperms
Ancestral lineage of angiosperms
fossil evidence of pollen
140 mya
Israel, morocco, Britain
Pollen wall with tectum and columella layer suggesting it is angiosperm pollen
what are monocots?
- Flower parts often in 3s
- Venation often parallel in leaves
- Very diverse: tiny or herbaceous or woody forms or tree forms
description of orchidaceae
Orchids
25,000 species (largest angiosperm family)
Largely tropical but not all
Flowers often with distinct labellum, androecium and gynoecium fused in column
reproduction of orchidaceae
Often with highly specialised interactions with pollinators eg. Labellum can mimic females of bee species (colour, feel and smell) and are pollinated by males trying to mate
Pollen in the column
economic importance of orchidaceae
Oncidium is an important horticultural group
Vanilla
what are poaceae? how do they reproduce? why are they econimically important?
- grasses
- wind pollination
- rice, wheat, maize
what are the monocots?
orchidaceae and poaceae
what are the eudicots?
- ranunculales, proteales, rosids and asterids
what are ranunculales?
- Important horticultural plants
- Poison darts
- Poppy seeds and opium
what are the proteales?
- Gondwana distribution
- Grevilleoideae such as banksias (paired flowers)
- Secondary pollen presentation by stigmas
- Pollinated by vertebrates
- Protea
what are the rosids?
flowers with distinct parts like fabaceae, rosaceae, mrytaceae and brassicaceae
fabaceae
- Nearly 10% of all eudicots
- Herbs, shrubs, trees, vines
- Often with root nodules harbouring N-fixing bacteria
- Economically important: legumes, clover
Acacia:
True acacias are in Australia and nearby
rosaceae
- 3000 species, mostly woody, abundant in N hemisphere
- Apples, pears, cherries and many other fruits
myrtaceae
- Trees and shrubs, mostly tropical and temperature species
- Eucalyptus, Corymbia, Angophora (all eucalypts)
brassicaceae
- Flowers with distinct cruciform pattern
- mustard family, kale, broccoli, turnips, radishes, canola
- Pungent compounds
what are the asterids?
flowers with fused petals, often with epipetalous stamens
- solanaceae
- laminaceae
- campanulacea
- asteraceae
solanaceae
- Potatoes and tomatoes and tobacco
- Flowers mostly corolla forming a wheel or funnel
- Calyx may be persistent on fruit
- Many species with poisonous alkaloids
laminaceae
- Most members have flowers with 2 + 3 corollas forming two opposing lobes
- Mint family, herbs, lavender
campanulaceae
- Widely distributed
- Stamens fused or nearly so, often forming a tube around the style
- Plunger pollination is common: pushes pollen out of the tube
asteraceae
- Largest eudicot family
- Composite: daisies, everlastings
- Composites are not single flowers but a cluster of flowers
- Sunflowers and weed species like dandelions
describe the angiosperm divergence
- A whole genome-duplication underlies the radiation of angiosperms: provided evolutionary opportunities
- Occurred in carboniferous
