Fruits and seeds

ACHENES

ACHENES

• One-seeded fruit
• Pericarp free from the seed
• Sunflower “seeds”

SAMARAS

• Winged achenes
• Dispersed by wind
• Fruit in maple trees and ash trees

Grains

• Also called caryopsis
• Single seeded fruits
• Pericarp fused to seed coat
• Fruits of all cereal grasses: wheat, rice, corn and barley

Wheat grain

Fused seed

coat and ovary

wall layers

Nuts

• One-seeded fruits
• Hard stony pericarps
• Hazelnuts, chestnuts, and acorns
• Other things commonly called nuts that are not true nuts but are actually seeds

Fruit Types II: Aggregate fruits

• Develop from a single flower with many separate carpels
• Raspberries and blackberries
• Strawberries also contain accessory tissue
• Seeds on the surface are actually separate achenes inserted on the enlarged, fleshy, red receptacle