Fruits

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