Flowers, Fruits, and Seeds

Most herbs: Dicotyledons!

Monocotyledons vs Dicotyledons Monocots More advanced plants One primary leaf Adventitious root system Flower parts arranged in 3’s Leaf veins: parallel. Vascular cambium absent Vascular bundles scattered throughout tissue Dicots More primitive Two primary leaves Tap root system Flower parts arranged in 4’s or 5’s. Leave veins: network system Vascular cambium present Vascular bundles in a ring (‘vein’)

Flower Structure Each flower grows from an embryonic primordium  forms the bud. Inflorescences - Group of several to hundreds of flowers. E.g. Maize

Flower Structure

Fruits Fruit:= matured & developed ovary and accessory parts that have developed and matured. Normally contains seeds. All fruits develop from flower ovaries (therefore found exclusively in flowering plants)

Fruit Regions

Fruit Fleshy Dry Berries Drupes Pomes Dry Those that split at maturity (Dehiscent) Those that don’t split at maturity (Indehiscent)

Fleshy Fruit Simple fruit (e.g. Drupe) Berry Aggregate fruit Multiple fruit Pomes (not true fruit)

Dry fruit Dehiscent Indihescent Follicle Capsule Legume Silique Achene Grain Nuts Shizocarp Samara

Fruits Fleshy Fruits Simple fleshy fruits: develop from a flower with a single pistil. Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Fleshy Fruit E.g. Drupe - Simple fleshy fruit with a single seed enclosed by a hard, stony endocarp (pit).

Fruits Berry: Develops from a compound ovary. Contains more than one seed. True berry: fruit with a thin skin and soft pericarp (e.g. tomato). Copyright © McGraw-Hill Companies Permission Required for Reproduction or Display

Berries Pepos - Thick skins/exocarps (Pumpkins).

Berries Hesperidium – Fruits with leathery exocarps containing oil glands (e.g. Citrus fruit).

Fruits Pomes – (not a true fruit) Pome: Accessory fruit with thick hypanthium. 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

Fruits Aggregate Fruits Develop from a single flower with numerous pistils. Pistils mature as a clustered unit on a single receptacle E.g. Raspberries, Strawberries.                                                                                  

Fruits Multiple Fruits Develop from many individual flowers in a single inflorescence. E.g. Pineapples, Figs, Maize

Dry Fruits - Dehiscent Follicle - Splits along one side/seam.

Follicle

Dry Fruits - Dehiscent Legume (e.g. bean pod) Consists of one folded carpel Splits along two sides into 2 sections Each represents half the carpel. Some legume pods, such as carob and mesquite, are indehiscent and do not split open.

Dry Fruits - Dehiscent Silique - Splits along two sides with the seeds in a central position when the two halves separate. (Silique = Two carpels separated by a seed-bearing septum)

Dry Fruits - Dehiscent Capsules - Consist of at least two carpels, and split in a variety of ways.

Dry Fruits - Indehiscent Achene Single seed attached to pericarp Pericarp fused into husk Husk - Easily removed Eg: buckweed, sunflower seed Sunflower seed

Dry Fruits - Indehiscent Nut Single seed with hard pericarp/husk Cup or cluster of bracts form at base Hazel nuts: only true nuts Walnuts, cashews & pecans = drupes Brazil nuts = seeds of capsules

Dry Fruits - Indehiscent Grain One-seeded fruit/seed fused with seed coat (pericarp) Eg: wheat

Dry Fruits - Indehiscent Samara Pericarp forms wings Fx: aids in seed dispersal Can be single or double Eg: Elm tree

Dry Fruits - Indehiscent Schizocarp Whole seed separates to form 2 separate 1-seeded fruitlets E.g.: Apiaceae/carrot family

LESSON TAKE-AWAY Flower Parts Fruit Types