Post on 17-Dec-2015
Pollination and DispersalForm and Function
Pollination• Pollination is how gymnosperms (cone-
bearing seed plants) and angiosperms (flowering plants) carry out sexual reproduction.
• Pollen carries the male sex cells from one plant to the next, allowing plants to cross with other plants far away.
• A vector is a means of moving pollen from plant to plant. Vectors may be wind or animals.
Wind Pollination• All gymnosperms
are wind-pollinated.
• Flowering plants that are wind-pollinated have flowers that lack showy petals.
• Anthers and stigma are often long and sticky or feathery.
Bee Pollination• Honeybees seek nectar
and pollen.
• Bees can see ultraviolet, and home in on flowers that are blue, purple, or have UV markings. They have well-developed sense of smell.
• Bees prefer flat platform-shaped flowers or large, open tubes.
Hummingbird Pollination
• Hummingbirds seek nectar - LOTS of nectar.
• Hummingbirds don’t have a good sense of smell. They see orange and red the best.
• Hummingbirds sip from pendulous tube-shaped flowers that other nectar-feeders can’t access.
Butterfly Pollination
• Butterflies seek nectar.
• Butterflies are attracted to platform-shaped flowers or clusters of very small, upright, tubular flowers.
• Butterflies have a keen sense of smell, and can see orange, yellow, blues, and purples.
Moth Pollination• Moths seek
nectar.
• Moths have a well-developed sense of smell.
• Moths are attracted to highly-scented, tubular, bright white flowers.
Who is the Pollinator?
Scarlet Gilia
Unscented, nectar-rich
Moonflower
Evening-blooming, highly scented
Aster
Nectar and pollen rich
Ceanothus
Pollen rich
Nicotiana
Evening-blooming, highly scented
Fuchsia
Unscented, nectar-rich
Borage
Good pollen and nectar source
Echniacea
Abundant pollen, good nectar source
Asclepias
Good source of nectar and pollen
Foxglove
Good nectar and pollen source
Yucca
Scented, nectar-rich
Buddleia
Highly-scented, nectar rich
Agastache
Nectar-rich
Liatris
Good source of nectar and pollen
Rudbeckia
Abundant pollen, good nectar source
WORK
TOGETHER
Observe these two gardens. What have they been planted to
attract?
Fruit Dispersal
Dispersal• Once a fruit and seeds have formed, it’s
essential for the seed to be moved away from the parent plant to avoid competition.
• As with pollination, seed dispersal involves many different vectors.
• Adaptations that we see on fruits and seeds helps tell us what the dispersal vector is.
Ballistic dispersal• Some plants
disperse their seeds themselves.
• Explosive dry fruits that shatter on contact or when shaken throw seeds far from the parent plant. Some fruits use build up hydraulic pressure until they burst.
Wind dispersal
• Lightweight dry fruits with wings, parachutes, and similar wind-catching structures can be blown away from the parent plant.
Water dispersal
• Hollow, water-resistant fruits can be dispersed long distances by moving water.
Animal dispersal
• Two types of fruits are animal dispersed:
• Fruits that can cling to fur.
• Edible fruits whose seeds can go through a digestive system, or may get discarded when the animal eats.
How is it dispersed?
Mangrove
Hollow, floating fruits. This tree grows in salt water swamps.
Cherry
Fleshy, sweet-tasting fruit with a hard pit.
Thistle
Small, dry fruits have long feathery threads extending from them.
Bedstraw
Fruits are small, sticky, with small barbs.
Squirting Cucumber
Pressure builds inside of the fruit until it
finally pops off of the stem. Juices with
slippery seeds squirt out.