III. Plant Diversity

B. Tracheophyte Origins

1. The Rhyniophyta

-vascular system of phloem and xylem

III. Plant Diversity

B. Tracheophyte Origins

1. The Rhyniophyta

Silurian – 440 mya

-vascular system of phloem and xylem

-“tracheids” in sporophytes

-- water and nutrient distribution

Gymnosperms Angiosperms

III. Plant Diversity

B. Tracheophyte Origins

1. The Rhyniophyta

-vascular system of phloem and xylem

-“tracheids” in sporophytes

-- water and nutrient distribution

-- lignin and support

III. Plant Diversity

B. Tracheophyte Origins

4. Life History: simple (primitive) - Homospory

III. Plant Diversity

C. Non-seed Tracheophytes

1. Lycophytes

(Club Mosses)

III. Plant Diversity

C. Non-seed Tracheophytes

1. Lycophytes - (Club Mosses)

- ancient; dominated first “forests” 300-350 mya

Lepidodendron - 45m -Carboniferous

III. Plant Diversity

C. Non-seed Tracheophytes

1. Lycophytes - (Club Mosses)

- ancient; dominated first “forests” 300-350 mya

- simple leaves

III. Plant Diversity

C. Non-seed Tracheophytes

1. Lycophytes - (Club Mosses)

- ancient; dominated first “forests” 300-350 mya

- simple leaves

- Dominant Sporophyte

(with stobili)

III. Plant Diversity

C. Non-seed Tracheophytes

1. Lycophytes - (Club Mosses)

III. Plant Diversity

C. Non-seed Tracheophytes

1. Ferns “and their allies”

III. Plant Diversity

C. Non-seed Tracheophytes

1. Ferns “and their allies”

- true complex leaves

III. Plant Diversity

C. Non-seed Tracheophytes

1. Ferns “and their allies”

- true complex leaves

- true roots

III. Plant Diversity

C. Non-seed Tracheophytes

2. Ferns “and their allies”

- true complex leaves

- true roots

- also ancient; appearing 350 mya

- dominant sporophyte; reduced gametophyte

Fern Life Cycle:

III. Plant Diversity

D. Seed Tracheophytes

- heterospory

III. Plant Diversity

D. Seed Tracheophytes

- heterospory

- seeds: lipid-rich endosperm packaged with

the zygote

III. Plant Diversity

D. Seed Tracheophytes

1. General Characteristics- heterospory- seeds: lipid-rich endosperm packaged with the zygote-pollen: - no more swimming sperm!!

III. Plant Diversity

D. Seed Tracheophytes

2. Gymnosperms – “naked seed”a. Evolutionary History

- dominated during Permian (280 mya) and through Mesozoic, and still dominate in dry env. Today (high latitudes, sandy soils)

III. Plant Diversity

D. Seed Tracheophytes

2. Gymnosperms – “naked seed”a. Evolutionary History

- dominated during Permian (280 mya) and through Mesozoic, and still dominate in dry env. Today (high latitudes, sandy soils)

b. Diversity- cycads- ginko - Gnetales - conifers

III. Plant Diversity

D. Seed Tracheophytes

c. Gymnosperm Life Cycle

III. Plant Diversity

D. Seed Tracheophytes

3. Angiosperms – “flowering plants”

- double fertilization

- triploid endosperm

III. Plant Diversity

D. Seed Tracheophytes

3. Angiosperms

- double fertilization

- triploid endosperm

- fruits

- flowers

Both serve to bribe animals to disperse either

Pollen or seeds NON-RANDOMLY. More likely to end up in a similar habitat.

III. Plant Diversity

D. Seed Tracheophytes

3. Angiosperms

- Angiosperm History

III. Plant Diversity

D. Seed Tracheophytes

3. Angiosperms

- Angiosperm History

- Diversity

- evolutionary trends:

primitive derived

insect pollinated wind pollinated

terrestrial aquatic

“woody” herbaceous