Fruits and Their Dispersal How Plants Get Around

Fruits Fruit is an ovary and its accessory parts that have developed and matured. Usually contains seeds. All fruits develop from flower ovaries and accordingly are found exclusively in flowering plants.

Fruits Fruit Regions Exocarp - Skin Endocarp - Inner boundary around seed(s). Mesocarp - Fleshy tissue between exocarp and endocarp. Three regions are collectively called the pericarp.

Drupes Multiple Fruits Types of Fleshy Fruits Berries Aggregate Fruits hesperidium pepo pome Multiple Fruits

Fruits Fleshy Fruits Simple fleshy fruits develop from a flower with a single pistil. Drupe - Simple fleshy fruit with a single seed enclosed by a hard, stony endocarp, or pit. Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Fruits Berry - Usually develops from a compound ovary and often contains more than one seed. True berry is a fruit with a thin skin and a relatively soft pericarp. Pepos - Relatively thick rinds (Pumpkins). Hesperidium - Leathery skin containing oils (Citrus). Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Fruits Pomes - Bulk of flesh comes from enlarged floral tube or receptacle that grows up around the ovary. (Apples) Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Dry Fruits that Split Dry Fruits that Do Not follicle legume silique capsule achene nuts caryopsis samara shizocarp Dry Fruits that Do Not

Fruits Dry Fruits That Split at Maturity (Dehiscent) Follicle - Splits along one side or seam. Legume - Splits along two sides or seams. Silique - Splits along two sides or seams, but seeds are borne on central partition exposed when the two halves separate. Capsules - Consist of at least two carpels, and split in a variety of ways.

Peas and Bean Pods are Legumes Milkweed Pod is a Follicle Follicles split on one side Peas and Bean Pods are Legumes Legumes split on 2 sides

Capsules split on more than 2 sides Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display Capsules split on more than 2 sides Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Siliques and Silicles

Fruits Dry Fruits That Do Not Split at Maturity (Indehiscent) Achene Nut Grain Samara Schizocarp Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

The fruits of grasses are called Caryopsis

Maple and Elm Fruits are called Milkweed follicle Elm Maple and Elm Fruits are called Samaras Elm Maple

Wild Carrot Queen Anne’s Lace

Fruits Aggregate Fruits Multiple Fruits Derived from a single flower with several to many pistils. Individual pistils mature as a clustered unit on a single receptacle Raspberries, Strawberry. Multiple Fruits Derived from several to many individual flowers in a single inflorescence. Mulberries, Pineapples, Figs

Raspberries, Blackberries are Multiples They are fruits derived from flowers with multiple ovaries

Aggregate Fruits: Mulberry The fruit is from an aggregate of flowers Pistillate flowers

Aggregate Fruits: Pineapple The fruit is from an aggregate of flowers

Strawberries are Accessory Fruits The fruit develops from as accessory part of the flower; the receptacle

Fruits serve many functions in the plant world Food source for the germinating seedling Plants need to get around. They do this with their fruits. Adaptations for dispersal

Fruit and Seed Dispersal Physical Carriers Wind Dispersal Small and Lightweight seeds. Water Dispersal Some fruits contain trapped air. Mechanical Ejection of Seeds

Coconuts are Water Dispersed

Fruit and Seed Dispersal Biological Carriers Animal Dispersal Seeds pass through digestive tract. Fruits and seeds catch in fur or feathers. Oils attract ants.

How Ripened Fruits Attract Animals Softer, easier to digest More fragrant Brightly colored Increase in sugar content is a source of carbohydrates (reward)

Pithecellobium oblongum fruit shows some of the traits often found in the fruits of bird-dispersed seeds This image of a ripe dehiscent Pithecellobium oblongum fruit shows some of the traits often found in the fruits of bird-dispersed seeds. The fruit wall is red as a flag for visibility at a distance (remember the red hummingbird-pollinated flowers). Closer up, the black seed contrasts strongly with both the red fruit and the white edible aril on its top (the aril is an outgrowth of the ovary wall, normally covering all or part of the seed as bait for the dispersal agent, especially when the fruit wall (ovary) itself is either a flag or purely protective). The bird snatches the seed+aril in flight and either swallows the entire unit (to later defecate or regurgitate the seed) or picks off the sweet aril and drops the seed.

Fruits and Dispersal Fruits remain distasteful to most animals (including humans) until they are ripe This ensures that the fruit will not be eaten until the seeds are mature

Animal Dispersal Long distance dispersal by birds: fruits and seeds trapped in the mud on their feet Seeds released in excrement Animals eat fruit, the seeds pass through the digestive tract. Scarification by digestive enzymes is necessary for germination

Mechanical Ejection Geranium fruit exploding Legume (Pea seeds) A combination of ejection and attraction

Mechanical Ejection Impatiens Fruit Exploding

What does this fruit want? Wild Cucumber