Divisions of Seed Plants

Div: Gnetophyta The “Gnetophytes” n From Triassic Period 200 mya. n Genera: Ephedra n n Genera: Gnetum n n Genera: Welwitschia n

Div: Gnetophyta The “Gnetophytes” n 1. Are gymnosperms. n 2. Have vessels as well as tracheids. n 3. Interval between pollination and fertilization is short. n 4. Mostly dioecious. n 5. Embryogeny has a more limited free nuclear period. n 6. Pollen chamber extends to female gametophyte - short pollen tube rapid fertilization.

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n 1. Resembles whisk ferns. n 2. Most of the photosynthesis occurs in new branches. n 3. Leaves appressed against stem. n 24-3

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n 1. Resembles whisk ferns. n 2. Most of the photosynthesis occurs in new branches. n 3. Leaves appressed against stem. n Ephedrine Chinese 2737 B.C. n 24-3

Div: Gnetophyta Order: Ephedrales Genus: Ephedra

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n 1. Resembles whisk ferns. n 2. Most of the photosynthesis occurs in new branches. n 3. Leaves appressed against stem. n 4. Compound megastrobili and simple microstrobili. n 24-6 C, D, E

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n 1. Resembles whisk ferns. n 2. Most of the photosynthesis occurs in new branches. n 3. Leaves appressed against stem. n 4. Compound megastrobili and simple microstrobili. n 24-6 C, D, E

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n 1. Resembles whisk ferns. n 2. Most of the photosynthesis occurs in new branches. n 3. Leaves appressed against stem. n 4. Compound megastrobili and simple microstrobili. n 24-6 C, D, E

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n Microsporophylls on Bractioles

Div: Gnetophyta Order: Gnetales Geneus: Ephedra

n Young ovule:

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n Mature ovule: n 24-12

Div: Gnetophyta Order: Gnetales Geneus: Ephedra n Embryonic Development:

Div: Gnetophyta Order: Gnetales Genus: Gnetum n plt n Microsporanium and ovules n n nodal collar

Div: Gnetophyta Order: Welwitschiales Genus:Welwitschia n 1. Long underground stems. n 2. Straplike leaves - basal meristem. n (intercalary growth)

Div: Gnetophyta Order: Welwitschiales Genus:Welwitschia n cones n 24-22C

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” arose during Jurassic Period 140 mya

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid endosperm (3n)

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid endosperm n Female sac (megagametophyte) has 8 nuclei: –antipodals (3) –polar (2) –synergids (2), egg (n) n Fertilization: –sperm nuclei (n) + synergid (n) --> embryo (2n) –sperm nuclei (n ) + 2 polar nuclei (n, n) --> Endosperm (3n)

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid (3n) endosperm n 3. Ovules and seeds are enclosed in a carpel

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid (3n) endosperm n 3. Ovules and seeds are enclosed in a carpel. n Evolution of carpel and stamen

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid (3n) endosperm n 3. Ovules and seeds are enclosed in a carpel n 4. Have flowers

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n Flower structure: –gynecium –Androecium –petals –sepals –receptacle –complete –perfect –monoecious –dioecious

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms”

Pollination in Angiosperms

Ovary Position in Angiosperms n Orthotropous Amphitropous n Anatropous Campylotropous

Compound Ovary X-section of a Lillium Ovary n Placentation: n Axile n Parietal n Free Central

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n Primitive Flower Structure: n Have many parts spirally arranged. n Magnoliaceae -->

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms”

n Advanced Flower: n A smaller and definite number of flower parts arranged alternate, opposite or whorled. n Orchidaceae -->

Angiosperm Life Cycle

Fertilization in Angiosperms

Evolutionary Adaptations for pollination in Angiosperms n Pollinators and plants have evolved together. n Bird pollinated flowers are red; bee pollinated, blue. n Nectar guides - in ultraviolet. n Long stamen - positioned to brush against pollinator. n Sunken ovary - inferior. n Lack of petals and stamen. n Flowers only open at night.

Ovary Position

Inflorescences -arrangement of flowers on the flowering stem n solitary n Spike n raceme n cyme n umbel

Inflorescences -arrangement of flowers on the flowering stem n compound umbel n head n n panicle

Inflorescences -arrangement of flowers on the flowering stem n Head

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid (3n) endosperm n 3. Ovules and seeds are enclosed in a carpel n 4. Have flowers n 5. Produce fruit

Fruit (Pericarp)- ripened ovary. n Pericarp layers: n Exocarp n Mesocarp n Endocarp

Fruit - ripened (matured) ovary. n Dry Indehiscent: n achene - n one-seeded with close fitting pericarp (sunflower) n Samara (Shizocarp) - n Like achene but with wing(s) n (ash, maple) n Caryopsis - n One-seeded pericarp fused to seed (corn) n Nut - n More than one carpel; hard, woody pericarp (acorn)

Fruit - ripened ovary. n Dry Dehiscent: n Legume n Pod opening on two sides n Follicle n Pod opening on one side n Capsule n Opens in a variety of ways

Fruit - ripened (matured) ovary.

Fruit - ripened ovary. n Fleshy: n Berry n Soft fleshy meso and endocarp (grape) n Drupe n Mesocarp fleshy; endocarp hard and stoney (peach) n Hesperidium n Berry withhard leathery rind;more than one locule (citrus fruits) n Pepo n Like hesperidium but one locule (squash) n Pome n fleshy part develops from pericarp and receptacle (apple) n Hip n achenes in a cup-like receptacle

Fruit - ripened (matured) ovary.

Fruit - ripened ovary. n Aggregate n Formed from more than one carpel of a single flower n (rapsberry) n Multiple n Formed from more than oner flower

Div: Magnoliophyta (Anthophyta) The “Flowering Plants”, “Angiosperms” n 1. Double fertilization n 2. Produces triploid (3n) endosperm n 3. Ovules and seeds are enclosed in a carpel n 4. Have flowers n 5. Produce fruit n 6. Xylem contains vessel elements and fibers. n 7. Phloem contains companion cells

Class:Magnoliopsida (dicots) vs. Class: Liliopsida (monocots)

Pits and Plasmodesmata

Tracheids to Vessels

Sieve Tubes and Companion Cells

Apical Metistems and Lateral Meristems (Primary and Secondary Growth)

Eudicot Pattern of Primary Tissues

Angiosperm Life Cycles n Annual n Biennial n Perennial

Stem Comparisons n Eudicot n Monocot

Older Eudicot Stem

Root Morphology

Taproot vs. Fibrous Root Systems

Root Development (Tip)

Root Development

Leaf Morphology

Leaf Morphology and Adaptation

Early Development of a Eudicot

Angiosperm Seeds

Monocot vs. Dicot Seeds

Seed Dormancy and Germination

Seed Germination n n n n n n

Vegetative Reproduction new plant from a vegetative structure n Stolons - “runners” n Rhizomes - n Corms - n Tubers - n bulbs - n Tip Layering - n suckers -

Origin of Angiosperms n * carpels n * double fertilization n * seeds in fruits n * tracheids but no vessels n Amborella

Origin of Angiosperms