Transcript Document
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. Types of Fleshy Fruits Drupes Aggregate Fruits Berries hesperidium pepo pome Multiple Fruits • Fleshy Fruits 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 •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. Milkweed Pod is a Follicle Follicles split on one side Peas and Bean Pods are Legumes Legumes split on 2 sides Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display 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 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 Milkweed follicle Elm Elm Maple Maple and Elm Fruits are called Samaras Wild Carrot Queen Anne’s Lace Fruits • Aggregate 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 Mulberry Fruit 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 1. Wind Dispersal – Small and Lightweight seeds. 2. Water Dispersal – Some fruits contain trapped air. 3. 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 1. Softer, easier to digest 2. More fragrant 3. Brightly colored 4. 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 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