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.