Identify which parts of the flower develop into the fruit and the seed.
Distinguish between fleshy and dry fruit.
Distinguish between aggregate and multiple fruit.
Understand the function of fruit in seed dispersal.
Solutions
A fruit is a matured ovary plus accessory parts, including seeds. They contain exo-, meso-, and endocarp tissue, altogether making the pericarp. The seeds are separate from and protected by the paricarp. The fruit may or may not include adjacent flower parts, and may or may not be from more than 1 ovary.
Some or all parts of the flower carpels can associate with the mature ovary to become fruit. Basically: ovary and accessories = fruit, ovules = seeds.
Aggregate fruit comes from multiple carpels in one flower, and have fruitlets. Multiple fruit comes from multiple flowers in one inflorescence.
Fruit seeds can be dispersed by wind if it or it's hairs are light, or if it has wings. It can be dispersed by animal if it can stick to it's fur or feathers, survive the digestive tract, or has oils to attract ants. It can be dispersed by water if it has trapped air for buoyancy.
Notes
Fruits
Matured ovary and accessory parts
Contains seeds
Botanical and culinary classification
3 layers to fruit, from outermost to innermost:
Exocarp
Mesocarp
Endocarp
All 3 together is called the pericarp
Seed is separate from fruit
Inside the endocarp
Protected by the fruit
Variability
Can consist of only ovary and seeds
Can include adjacent flower parts
May be fleshy or dry at maturity (grape vs beans)
May be dehiscent (split open) or indehiscent (not split open)
May be derived from more than one ovary
We may eat the fruits at "immature" stages
Fruits are Mature Ovaries
Some or all of the parts of flower carpels (female parts) can associate with the matured ovary to become accessory tissue during maturation.
Apple Blossom Anatomy
Petals make up the corolla
Stamen with pollen producing anthers stop a filament (stalk)
Stigmas on the end of stalks called styles lead to the ovary (pistil = stigma, style, and ovary)
Sepals make up the calyx
Ovary with ovules; ovary becomes the core and ovules the seed
Hypanthium: tissue connecting sepals, petals, and stamen; enlarges to become the part we eat
Simple Fruits
Develop from a single carpel, or from two or more united carpels.
Can be dry or fleshy at maturity
ex: bean pods, cherries, tomatoes
Aggregate Fruits
Develop from multiple carpels in a single flower that retain their identities in the mature state
Individual matured carpels are called "fruitlets"
ex: magnolias, raspberries, strawberries
Multiple Fruits
Develop from an inflorescence or the carpels of many fused flowers
ex: mulberry, pineapple
Simple Fruits cont.
Contains the most diversity within group
When ripe, can be fleshy or mostly dry
Fleshy
Dry (Dehiscent)
Dry (Indehiscent)
Berries
Pepo
Hesperidium
Drupes
Pomes
Legumes
Follicles
Capsule
Achene
Nut
Samara
Grain
Schizocarp
Berries
A simple fleshy fruit in which the ovary wall or at least it's inner portions become enlarged and usually juicy (grape, banana, gooseberry)
Special types include:
Pepo: berry in which a relatively hard rind is formed; the interior of fruit not divided by septa (ex: watermelon, gourds, squash)
Hesperidium: berry in which a leathery rind forms; the interior of the fruit is divided by septa, indicating the number of sepals (ex: citrus)
Drupes
Fleshy simple fruit that are one-seeded and develop from a superior ovary in which the endocarp becomes hard and stony, the exocarp becomes a relatively thing skin, and the mesocarp becomes either fleshy or fibrous (ex: peaches)
Pomes
Simple accessory fleshy fruits that are formed by a group of more or less firmly united with each other and surround by and united to the floral tube or recepticle (ex: apples)
Dehiscent Fruits
Dry fruits which at maturity open by definite natural means to shed the contained seeds
Legume
Developed from one carpel at maturity splitting along both the central and dorsal sutures (ex: beans, peas)
Follicle
Developed from 1 carpel and at maturity splitting along only one suture
Capsule
Fruit developed from several sutures
Following 5 bullets not necessary to memorize:
loculicidal: splits along the outer median line
septicidal: splits along the septa and opens at the top (ex: yucca, agave)
silique: a special long slender capsule of 2 carpels (ex: mustard)
pyxis: has circumscissile dehiscence (ex: plantain, amaranths, pursland)
poricidal: ones with round holes (ex: poppies)
Indehiscent fruits
Dry fruits which do not open when mature to shed their seeds; many are one-seeded fruits
Achene: one-seeded, dry, indehiscent fruit; the one seed is attached to the fruit wall at a single point (ex: buttercups, dandelion, sunflower)
Nut: a dry, indehischent, one-seeded fruit similar to an achene but with the wall greatly thickened and hardened (ex: beech, chestbut, oak, hazel, walnut, hickory)
Samara: one- or two-seeded dry, indehiscnet fruit in which part of the fruit wall grows out into a wing (ex: elm, maple, oak)
Grain: one-seeded, dry, indehiscent fruit in which the fruit wall and the seed coat are fused (ex: wheat, corn, grasses)
Schizocarp: formed from several carpels, each carpel of this pistil enclosing a single ovule, at maturity the carpels separate as separate indehiscent fruits (ex: mallow, wild carrot, dill)
Fruit and Seed Dispersal
Dispersal by wind
Fruits: samaras, plumes, or hairs on fruit
Seeds: small or lightweight, or with wings
Dispersal by animal
Seeds pass through digestive tract
Fruits and seeds adhere to fur or feathers
Oil attracts ants
Elaiosomes on bleeding hearts used as food by ants
Water dispersal
Some fruits contain trapped air for flotation
Con Fruit Be Male or Female?
Fruits themselves do not have sexes; they are the product of male/female parts of plants