1. Fruits
Plant Science
Unit 2

2. Fruit
In flowering plants – fruit is a mature ripened _________ that contains the seeds
A fruit is defined as a ripened ovary
Pericarp – the ovary wall
May consist of two or three layers: exocarp, mesocarp, endocarp

3. Pericarp

4. Fruit Types
Simple
Aggregate
Multiple

5. Simple Fruit
A simple fruit – develops from a single ovary of a single flower
Can be either fleshy or dry when mature
Simple fleshy fruit
Berry

6. Simple Fleshy Fruit
Berry – entire fruit wall is soft and fleshy at maturity. Inside is slimy. Contains no stony layer but contains one to many seeds.
Examples: Grapes, tomatoes, etc
Hesperidium - a berry with a tough, leathery rind (peel)
Examples: Oranges, lemons, other citrus

7. Simple Fleshy Fruit
Drupe – outer part of fruit wall is soft and fleshy, inner part is hard and stony. Has a pit.
Examples: Peach, plum, cherries

8. Simple Fleshy Fruit
4. Pepo – also a fleshy fruit with a tough outer rind
All members of the squash family: pumpkin, melon, cucumber

9. Simple Fleshy Fruit
Pomes: most of the fleshy part of pomes develops from the enlarged base of the perianth (corolla and calyx) that has fused with the ovary wall
Examples: Pears, apples

10. Simple Dry Fruits
Simple dry fruits are dry (not fleshy) at maturity. Simple dry fruits that open at maturity include capsules and legumes
Capsule – fruit is dry at maturity and splits open along several seams
Example: Cotton

11. Simple Dry Fruit
Legumes are dry at maturity and split open along __________ seams
Examples: pea pods, bean pods, peanut

12. Simple Dry Fruits
Simple dry fruits that do NOT open at maturity include:
Caryopsis: seed coat is fused to the ovary wall
Examples: corn, wheat
Nuts: single-ovary wall and seed coat remain separate, ovary wall is very hard
Example: acorn s

13. Aggregate Fruit
An aggregate fruit develops from one flower with many separate pistils/carpels, all ripening simultaneously
Examples: strawberry, raspberry, blackberry

14. Multiple Fruit
Multiple fruit develops from ovaries of several flowers borne/fused together on the same stalk
Example: pineapple

15. What is the purpose of the fruit?
The main function of the fruit is to disperse the seeds
Dispersal is important because
It spreads the progeny in order to colonize new environments
Reduces the chances of predators destroying all of the plant’s yearly seed production
Reduces plant competition
4 types of dispersal

16. Self Dispersal
Plants disperse their seeds by forceful ejection – explosive fruits!
Witch hazel, squirting cucumber (jet propulsion)

17. Self Dispersal The peanut plant sows (buries) its own seeds!
Geocarpic: carpel grows inside the earth

18. Wind Dispersal
Fruit and seeds may have special devices for wind dispersal
Plumes catch wind currents: dandelion
Trees take advantage of their great heights for wind dispersal. Fruits with wings are used to slow the descent to land: maple, ash fruit

19. Water Dispersal
Fruits and/or seeds use flotation devices to travel by water
Fruit may have air spaces, waterproof coverings, and corky floats
Example: coconuts

20. Animal Dispersal Some dry fruit attach and cling to animals
Some have velcro-like hooks that cling to animal fur (burdock, cockleburs)
Others that sticky substances that stick to host (mistletoe)

21. Check it out! http://www.vtaide.com/png/seed-dispersion.htm
Gives more examples of how specific fruits are dispersed