Flowers-Fruits & Seeds Lab
The purpose of this lab is to help you understand the basic anatomy of flowers, fruits & seeds and to make the conceptual links between them.
This lab will be a little different from others because we will have a lot of demonstrations of macroscopic and microscopic specimens which are related.
I am going to group things in Families as much as possible. This does NOT mean that these specimens are the most representative for that family. Family groupings may, however, help you understand and remember the structural connections between the Macroscopic and Microscopic.
FLOWERS
When you examine Flowers you should try to see the following.
Flower Organs: Note the presence or absence of Sepals, Petals, Stamens and Carpels.
Determine the Floral Symmetry (Actinomorphic vs Zygomorphic)
Look for Coalescence and Adnation.
Determine whether the Flowers are Hypogynous, Perigynous or Epigynous.
Determine whether the Placentation is Marginal, Parietal, Axile or Central.
Fruits
Due to the various developmental stages of fruits available, it may not be possible to determine all of the below from lab specimens. Illustrations in this document and from your lecture pages should help to fill in the missing data.
Note whether the Fruits are Simple, Aggregate or Multiple.
Determine whether the fruits are Fleshy or Dry at maturity.
Are they Dehiscent or Indehiscent?
Are the fruits Accessory?
Specifically identify the Fruit Type.
SEEDS
Examine the Seed Coat and note the presence of Sclereids.
Locate the Cotyledon(s) and/or Endosperm.
Note the Primary Storage Products (Only for specific DEMOS)
Locate the Embryonic Axis with its Root & Shoot Apical Meristems and note the locus of Cotyledon attachment.
Fabaceae (Leguminosae)
 Erythrina sandwichensis wiliwili |
 Bauhinia |
 Erythrina Flowers |
 Androecium & Gynoecium from Erythrina sp. |
 Leucaena Flower Cross-Section - Locate the Flower Organs! |
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 Leucaena Carpel longitudinal Section |
 Leucaena Ovule |
 Cross-Section through a Bean Ovary |
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 Long-Section through a Bean Seed |
 Typical Immature Legume Fruit
Examine Mature Examples of a Legume Fruit! |
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Cross-Sections through a Bean Seed at different levels |
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| Funiculus of Bean Seed | |
 Dissect a Hydrated legume Seed & identify the Major Structures |
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 Examine Macerated Seed Coats of Pea (Pisum) and identify the types of Sclereids present. |
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Solanaceae (Tomato/Potato Family)
Deadly Nightshade!!!!!!!!
 Burgmansia is called Angel's Trumpet. If you partake of this plant you will hear the real Angel's Trumpet!! Most members of this Family are highly TOXIC!!! |
 Flower similar to that of Burgmansia: Locate the External and Internal Flower Parts.
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 Long-Section of a tomato Flower Bud: Locate the relevant parts! |
 Adnation????? |
 Tomato Ovary Long-Section |
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 Comparison of Macroscopic & Microscopic views of Solanaceous Flowers |
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 Flower Cross-Section |
 Cross-Section through the Anthers and Stamens. |
| Observe the microsections of Tomato Ovaries!!!!! | |
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 Guess What!!!!!! |
Rutaceae (Citrus Family)
 Citrus Flowers & Young Fruits -> |
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 Citrus Androecium & Gynoecium Long-Section |
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 Cross-Section of a Citrus Ovary |
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Look at the Microscopic Slide of Citrus ovary X-Sec.!!! |
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 Guess What!!!!!!!!! |
Papaya (Carica papaya)
 Papaya Flowers & Fruits |
 Papaya Flower |
 Papaya Fruits |
 Papaya Gynoecium: Long Section |
 Cross-Section of a Mature Papaya Fruit |
 Microscopic View of an Immature Papaya Ovary with Parietal Placentation. |
Guava (Psidium guajava) Myrtaceae
 Guava Flower Long Section |
 Long Section through a Guava Ovary: The outer part of the fruit comes from the Hypanthium. |
 Eugenia Flower Ovary & Fruit |
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 Immature Guava Fruit |
 An Accessory Fruit if ever I saw one! |
 Eucalyptus Flowers & Fruits |
 Metrosideros polymorpha |
Cucurbitaceae (Cucumber Family)
 Cucumber Flowers & Fruits |
   Cucumber Ovary Long Section: H = Approximate location of the Hypanthium |
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 This is an Accessory Fruit |
 Cucumber Ovary Microscopic Cross-Section: This has Axile Placentation |
 A highly invasive member of this family |
 Placentation can be Parietal or Axile |
| This is an example of an Accessory fruit due to the fusion of the Hypanthium with the Pericarp. | |
Liliaceae & Agavaceae
 A Typical member of the Liliaceae: Note the Tepals & Superior Ovary. |
 Dianella sandwichensis (uki uki grass) was an important plant for ancient Hawaiians. They used its leaves to make Twine that was used to tie thatch to their houses. |
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 Cross-Section of a Lily Ovary |
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 Lily Capsule |
 Dehiscent Capsule of Brodiaea with Seeds |
 Immature Lily Embryo inside a developing Seed: |
 Cartoon of a Mature Lily Embryo in a Seed: ES = Endosperm, R = Root, SAM = Shoot Apical Meristem |
 Crinum Flowers have an Inferior Ovary |
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 Agave with an Inflorescence |
 Agave Flowers |
 Agave Flowers also have an Inferior Ovary |
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| Hawaiian ti is also in the Agavaceae | |
Malvaceae (Hibiscus Family)
 Stigmas!!!!! |
 Stamens!!!!!!!! |
| View Cross-Section of Cotton Ovary!!! | |
 Cotton Immature Fruit |
 Cotton Mature Fruit: Find the Seeds!!! |
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Asteraceae (Composite Flowers)
 Composite Inflorescence |
 Erigeron Flowers |
 Long Section through a Composite Inflorescence |
 Long Section of Erigeron Inflorescence |
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 Erigeron Disk Flowers |
 Fruits with pointed Stigmas |
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 Sunflower Fruit |
 Hesperoennia arbuscula: A Rare Hawaiian Endemic |
 Artichoke Inflorescence |
Cereal Fruit
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 Diagram of a Corn (Zea mays) Fruit: PC/Testa = Pericarp/Testa, CN = Cotyledonary Node, SAM = Shoot Apical Meristem, RAM = Root Apical Meristem |
 Wheat Fruit Long Section |
 Outer part of a Wheat Caryopsis: Note the Aleurone Layer and the Pericarp. The Seed Coat is fragmented and occupies the nearly empty space between the Aleurone and the Pericarp. The Light Blue areas in the Endosperm contain Storage Protein. The smaller, cream-colored organelles are Amyloplasts which store starch. |
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| Wheat Embryo: CR = Coleoptile, RCap = Root Cap, RAM = Root Apical Meristem, CN = Cotyledonary Node, SC/PC = Seed Coat/Pericarp, CT = Coleoptile, S = Scutellum, EN = Endosperm | |
| Examine Commercial Slides and Specimens stained with IKI and Sudan. | |
Multiple
Fruits
We will use Noni, Pineapple and Breadfruit to illustrate Multiple Fruits
 Noni Branches: Locate the Inflorescences along the stem at the Node. |
 Noni Inflorescences: The flowers are closely inserted on the Receptacle  |
 Noni Young Inflorescence and Nearly-mature Fruit |
 Noni Mature Fruit: Each Yellow Circle indicates one Flower that has contributed to this Multiple Fruit |
 Pineapple Plant that has resumed Vegetative Growth after it has formed an Inflorescence. |
 Young Pineapple Fruit: The showy red structures are the bracts which subtend each flower. |
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| Whole & Sectioned Pineapple Fruits. The fruits on the bottom were allowed to uptake a water-soluble stain for a long time.Each Segment of the Fruit has developed from its own Flower | |
 Pineapple Whole and Long Section showing the complexity of its Vascular System which is revealed by a dye. Locate the Flowers and the Receptacle! |
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 Jackfruit!!! |
 Breadfruit Staminate and Carpellate Inflorescences. each is composed of highly reduced Staminate or Carpellate Flowers |
 Breadfruit Staminate Flowers |
 Breadfruit Carpellate Flowers |
Types of Placentation
 The most Common Types of Placentae |
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 Leucaena - Marginal Placentation |
 Parietal Placentation |
 Axile Placentation |
 Central Placentation |
