3: Fruit Flashcards
What is a fruit?
a mature ovary that contains a seed
T or F: fruit provides nutrients for the seed
FALSE
What is the function of the fruit around the seed?
It is a means for seed dispersal because animals will ingest fleshy fruits and deposit them elsewhere ready to germinate or animal fur/wind will pick up and relocate dry fruits
What are the 4 kinds of fruits?
- Simple fleshy fruits
- Dry fruits
- Aggregate fruits
- Multiple fruits
Explain what simple fleshy fruits are. What are some characteristics of the flower ovary it was derived from?
Fruits that are fleshy/juicy and edible when mature. They develop from a flower with a single pistil, and they will rot or get eaten by animals to disperse seeds.
The ovary can be derived from a single carpel (simple ovary) or multiple carpels (compound ovary).
The ovary can be superior or inferior in the flower.
The ovary can develop into the fruit itself or other parts of the flower may develop with it
What are the three layers in a mature fruit? Describe each. What is the collective term for all 3?
- exocarp: outer layer/wall of ovary becomes the skin of the fleshy fruit
- mesocarp: middle layer/wall of ovary that will become the fleshy part we eat (usually)
- endocarp: the inner layer/wall of ovary, usually where the seed is held
Collective: Pericarp
What are the 5 groups of fleshy fruits?
- True berries
- Hesperidium (berry-like)
- Pepo (berry-like)
- Pome
- Drupe
What are the characteristics of true berries and give examples
- simple fleshy fruits
- soft throughout with thin easily peeled skin when mature
- contain more than one seed (with some exceptions)
- multiple carpels with locules = usually develop from a compound ovary
- the entire pericarp is fleshy, making it difficult to distinguish between the mesocarp and endocarp
ex. Grapes, tomatoes, kiwi, bananas, avocados, dates, peppers, eggplants
Define parthenocarpic berries and give an example
Berries that do not have seeds, the exception to the characteristic that makes true berries.
Ex. Bananas, but they have been selectively modified to not have seeds, their wild ancestor did have seeds
What are the characteristics of Hesperidium fruits? Give some examples
They are berry-like, simple, fleshy fruits that are:
- soft inside
- leathery exteriors with aromatic oil cavities in skin
- contain multiple carpels filled with sacs containing juice
- contain multiple seeds within the carpels = compound ovary
ex. grapefruits, limes, oranges, lemons
What are some characteristics of Pepo fruits? Give some examples
They are berry-like, simple, fleshy fruits that are:
- soft throughout
- have a hard/thick outer skin (rind) that is composed of receptacle tissues and cannot be peeled off
- contain many seeds clustered in the middle
- many carpels = compound ovary
ex. melons, cucumber, pumpkins, squashes
What are some characteristics of Pome fruits? Give some examples
- they are SIMPLE fleshy fruits
- they are derived from a flower with an inferior ovary embedded within the floral tube. The ovary will become the core and the floral tube will expand around the ovary to form the accessory tissue/hypanthium which is the fleshy part animals eat.
- endocarp is leathery or papery right around the seeds
ex. apples, pears, quinces
Define hypanthium
The floral tube outside the ovary that becomes the fleshy part of pome fruits (such as apples) that animals eat
What are the characteristics of a Drupe? Give examples
- simple, fleshy fruit
- usually contain only one seed enclosed in a hard, stony endocarp (usually a pit)
- usually develops from flowers with a superior ovary containing a single ovule
- mesocarp is not always fleshy (ex. coconut husks are the mesocarp and exocarp)
ex. coconuts, stone fruits (peaches, cherries, nectarines, plums, olives, almonds)
- almond seeds grow with husks too that are removed before marketing, then the seed that we consume is enclosed in a hard endocarp that must be cracked
Define placenta
the fleshy tissue in some fruits where the seeds are attached
ex. in bell peppers
Define locule
the cavity within the fruit where the seeds are located
Explain what dry fruits are. What are the two kinds?
Fruits whose mesocarps are dry at maturity.
- Dehiscent
- Indehiscent
Explain what dehiscent fruits are and list the 5 groups
Dry fruits that split at maturity
- follicle
- legume
- silique
- silicone
- capsule
Explain what indehiscent fruits are and list the 5 groups
Dry fruits that do not split at maturity, so the SINGLE seed remains fused with the pericarp
- nut
- caryopsis (grain)
- samara
- achene
- schizocarp
What are the characteristics of follicle fruits? Give examples
Dry, dehiscent fruits that split along ONE side or seam of the fruit only to expose the seeds.
Ex. milkweed, peony, columbine
What are the characteristics of legumes? Give examples
Dry, dehiscent fruits that split along TWO sides or seams of the fruit.
ex. peas, beans, lentils, carob, mesquite, most of the legume family (but not peanuts)
What are the characteristics of silique fruits? give examples
Dry, dehiscent fruits that split along TWO sides/seams of the fruit but the seeds are attached or embedded to a central partition which becomes exposed when the fruit splits
* very slender and long *
ex. brassicas
What are the characteristics of silicles? Give examples
Dry, dehiscent fruits that split along TWO sides/seams of the fruit but the seeds are attached or embedded to a central partition which becomes exposed when the fruit splits
* wide and circular *
ex. shepherd’s purse (brassica)
What are the characteristics of capsules? Give examples
- dry, dehiscent fruits that are most common
- contain at least 2 carpels and can split in a variety of ways
ex. Orchids, poppies, lilies, rhododendrons
What are the characteristics of nuts? give examples
Dry, dehiscent fruits that contain one seed
- the pericarp is very hard and woody
ex. acorns, hazelnuts
What are the characteristics of achenes? Give examples
Dry, dehiscent fruits
- only the base of the seed is attached to the pericarp, making the husk (pericarp) easy to separate from the seed
ex. sunflower ‘seeds’, buttercup, buckwheat, dandelions
What are the characteristics of samaras? Give examples
Dry, dehiscent fruits
- the pericarp surrounding the seed extends out into a wing structure or membrane, aiding in dispersal
ex. maples produce samaras in pairs
ex. tree of heaven, elms, ashes produce samaras in singles
What are the characteristics of caryopsis (grains)? Give examples
Dry, dehiscent fruits
- the pericarp is tightly fused with the seed and cannot be separated
ex. all members of Grass family including corn, wheat, rice, oats, barley
What are the characteristics of schizocarps? Give examples
Dry, dehiscent fruits
- they are composed of two fused twin fruits that upon maturing will break into two separate segments containing a single seed each
ex. most of the Apiaceae (parsley) family like dill, fennel, carrot, anise, caraway
Explain what aggregate fruits are and give examples
Compound fruits derived from a SINGLE FLOWER with MULTIPLE PISTILS.
Each pistil will develop into an individual tiny drupe and as the fruit matures, the individual drupes will fuse into one unit on a single receptacle
ex. raspberries, blackberries, strawberries (special case)
Explain what multiple fruits are and give examples
Compound fruits derived from MANY FLOWERS, each with a single pistil, in a single inflorescence.
As the flowers mature separately into fruitlets, they will develop together to form a single larger fruit
ex. mulberry, pineapples, figs
What are some methods of seed dispersal for fruits?
- wind (winged or plumed fruits) - ex. samaras
- ejection from seed pods when disturbed - ex. achenes
- water (ability to float long distances) - ex. coconuts
- animals can:
- ingest the attractive fruits
- store the fruit in caches
- pick up the fruit or seeds on their fur/hair/feet
What kind of fruit is an orange?
hesperidium - fleshy
What kind of fruit is an apple?
pome - fleshy
What kind of fruit is a strawberry?
aggregate - fleshy
What kind of fruit is a grape?
berry - fleshy
What kind of fruit is a peach?
drupe -fleshy
What kind of fruit is a watermelon?
pepo - fleshy
What does the outer flesh between the core and skin of a pome fruit (like an apple) come from?
the floral tube or hypanthium tissue (accessory tissue)
what is the botanical term for the ‘skin’ or outside of the ovary wall?
Exocarp
What is the term for the fruit types derived from a solitary flower that has more than one pistil (ovary)?
Aggregate
What is the botanical term for the hard pit inside of a drupe fruit called?
endocarp
What is the botanical term for the fleshy edible tissue between the skin and pit of a drupe?
mesocarp
Which of the following dry fruit types does NOT split at maturity?
a) samaras
b) follicles
c) legumes
d) capsules
a) samaras - the pericarp needs to soften and rot in order to release the seed
Compare & contrast (2 differences, 1 similarity) aggregate and multiple fruits. Give examples of each
SIMILARITY: Aggregate and multiple fruits are both types of compound fruits because they are derived from multiple ovaries (either within a single flower or multiple flowers with single ovaries = many pistils)
DIFFERENCE:
1. Aggregate fruits are derived from a single flower, whereas multiple fruits are derived from multiple flowers in an inflorescence
- Aggregate fruit flowers contain multiple pistils (ovaries) that each form little fruits/drupelets and mature into one single fruit - ex. raspberries. Whereas, multiple fruit flowers each contain a single pistil and each flower, as the fruit matures, will coalesce into one large fruit - ex. pineapples
Difference between a simple pistil and compound pistil. Which fruits are in which category?
SIMPLE: one flower, one pistil, one carpel
ex. follicles, legumes, achenes, nuts, grains, schizocarps, samaras, drupes
COMPOUND: one flower, one pistil, 2+ carpels
ex. silicles, siliques, capsules, most berries, pomes, pepos, hesperidiums
