Seed Dispersal LabSeed Dispersal Lab

Dispersal by WaterDispersal by Water

The coconut can float on water for long intervals The coconut can float on water for long intervals due to an air-filled pericarp layer.due to an air-filled pericarp layer.

Dispersal by WaterDispersal by Water

Mangrove seeds germinate while still attached to Mangrove seeds germinate while still attached to the adult plant. Seedlings are released into water. the adult plant. Seedlings are released into water.

Dispersal by WaterDispersal by Water

When its seed pod breaks open, Pond Iris When its seed pod breaks open, Pond Iris seeds fall into nearby water. Seeds can seeds fall into nearby water. Seeds can float for long distances and germinate either float for long distances and germinate either in the water or when they become lodged in in the water or when they become lodged in mud.mud.

Dispersal by WindDispersal by Wind

The feathery The feathery pappus helps carry pappus helps carry the dandelion seed the dandelion seed in an updraft. in an updraft.

Seeds with wings Seeds with wings have a slower have a slower descent when they descent when they fall from a tree. fall from a tree.

Dispersal by WindDispersal by Wind

The Red Campion ovary produces a The Red Campion ovary produces a “pepper pot” seed capsule with “pepper pot” seed capsule with openings at the top. Wind shakes the openings at the top. Wind shakes the capsule to scatter the seeds. capsule to scatter the seeds.

Dispersal by Animals: Fleshy FruitsDispersal by Animals: Fleshy Fruits

Animals eat the fruit and deposit the Animals eat the fruit and deposit the undigested seeds at another location. undigested seeds at another location.

PersimmonsPersimmons MulberriesMulberries

Dispersal by Animals: AttachmentDispersal by Animals: Attachment

The cockleburr fruit has hooked barbs for The cockleburr fruit has hooked barbs for

attaching to an animal’s fur or a bird’s feathers.attaching to an animal’s fur or a bird’s feathers.

Dispersal by Animals: AttachmentDispersal by Animals: Attachment

Mistletoe has a sticky fruit that attaches to the Mistletoe has a sticky fruit that attaches to the beak and faces of birds. Birds scrape their beak and faces of birds. Birds scrape their beaks on tree branches to spread the seeds. beaks on tree branches to spread the seeds.

Mechanical DispersalMechanical Dispersal

The seeds are released when a ripe The seeds are released when a ripe capsule of an Impatiens plant is touched. capsule of an Impatiens plant is touched.

Mechanical DispersalMechanical Dispersal

A thick husk that splits open to release a A thick husk that splits open to release a hickory nut. hickory nut.

Today’s LabToday’s Lab

• Survey of Seed Dispersal MechanismsSurvey of Seed Dispersal Mechanisms– Observe and draw seedsObserve and draw seeds

– Propose dispersal mechanismPropose dispersal mechanism

• Design and test a wind-dispersed seedDesign and test a wind-dispersed seed– Distance: Air stream testDistance: Air stream test

– Time airborne: Balcony testTime airborne: Balcony test