Fruit and seed types. Terminology Indehiscent – fruits that retain their seeds. Dehiscent –...

Fruit and seed types

Terminology• Indehiscent – fruits that retain their seeds.

• Dehiscent – fruits that release their seeds.

• Simple fruits - can be either dry or fleshy, and result from the ripening of a simple or compound ovary in a flower with only one pistil.

• Aggregate fruit - form from single flowers that have multiple carpels (style+stigma+ovary) which are not joined together, i.e. each pistil contains one carpel.

What is a fruit?• Fruit are developed from ovaries which contain

fertilised ovules (eggs).

• This definition doesn’t include many of the things we commonly think of as fruit and can make things confusing e.g. strawberries aren’t fruit but rather an accessory fruit made from other floral structures. The “seeds” on strawberries are really fruit!

• A fruit’s function is to disperse the seed by: wind, gliding, animals (eaten, stuck to fur), water, gravity or even jet propulsion (squirting cucumber).

Pericarp• The pericarp is what develops from the ovary

wall. It has three layers that widely in structure depending on the fruit:

• Exocarp – The outer layer.

• Mesocarp – The middle layer.

• Endocarp – The inner layer.

• Although botanically the pericarp is considered to be the fruit, what we often consider to be the fruit is actually made from floral parts other than the ovary wall.

Different types of fruit

• Different fruits are defined by the structure their 2 pericarp layers and how many carpels they are formed from.

What is a seed

• Seeds develop from ovules.

• As with fruit often what we think of as seeds aren’t (see strawberry example)

Indehiscent Fruit

• http://science.jburroughs.org/resources/flower/fruit3.html

Pomes

Pomes

Achene

Achene

Berries

Hesperidiums

Drupe

Drupe

Seed Dispersal Videos• Squirting cucumber

• http://www.youtube.com/watch?v=FfMbw9v1e40

• Popping seeds

• http://www.youtube.com/watch?v=F1sJX4bduCs&feature=related

• Private Life of Plants

• http://www.youtube.com/watch?v=zbQ1jWl3AOM&NR=1