Adaptation to Land??

1. Waxy cuticle. 2. Gametangia - antheridia and archegonia. 3. Embryos - young sporophytes contained

within protective tissues. 4. Pigments - protect against UV light. 5. Thick spore walls.

Classification of Plants

Evolution of Plants

K: Plantae Div: Hepatophyta

K: Plantae Div: Hepatophyta

-mitosis- Plant Body - Gametophyte (n) ----------->

---> Archegonium (n) ---> Eggs (n) ---> Antheridium (n) ---> Sperms (n)

Sperm + Egg ---> Zygote (2n) ---> *meiosis* Sporophyte (2n) ---> Sporocyte (2n) -----------> Spore Tetrad

(n) -mitosis- Spores (n) -----------> Plant Body - Gametophyte (n)

“Alternation of Generations”

K: Plantae Div: Hepatophyta

1. Gametophyte (n) dominant. 2. Most are simple land plants restricted to moist

environments. (No true vascular tissue.) Riccia

K: Plantae Div: Hepatophyta

1. Gametophyte (n) dominant. Usually flat thallus; bilobed leafy structures. Rhizoids unicellular or absent. 2. Most are simple land plants restricted to moist

environments. (No true vascular tissue.) Riccia 3. Contain Oil bodies (90% species). 4. Apical Growth and posterior decay. 5. Sporophyte (2n) enclosed within calyptra and pseudoperianth; seta may be present; elaters present. 6. Evolved during the Devonian Period (375 mya).

K: Plantae Div: HepatophytaGenus: Marchantia

1. Flat branches - thallus (plant body) may exceed 4 inches in length.

2. Surface of plant is cutinized. 3. Rhizoids emerge from ventral surface - tuberculate &

smooth. 4. Single layer of photosynthetic cells in air chamber.

5. Single epidermal layer top; parenchmatous layers below.

K: Plantae Div: HepatophytaGenus: Marchantia

6. Air pores - 4 tiers of cells (lower tier closes opening).

K: Plantae Div: HepatophytaGenus: Marchantia

7. Vegetative plants form gemmae cups (gemmae).

Like “fragmentation”

K: Plantae Div: HepatophytaGenus: Marchantia

K: Plantae Div: HepatophytaGenus: Marchantia

8. Sexual structures form on special branches - gametophores. antheridiophores & archegoniophores

K: Plantae Div: HepatophytaGenus: Marchantia

8. Sexual structures form on special branches - gametophores. antheridiophores

antheridia in chambers below dorsal surface of disc; in rows biflagellated sperms discharged

K: Plantae Div: HepatophytaGenus: Marchantia

8. Sexual structures form on special branches - gametophores. archigoniophores

archegonia in chambers on ventral surface between arms; in rows Egg at base. venter, pseudoperinanth, involucre, calyptra, capsule, stipe, foot

K: Plantae Div: Hepatophyta

-mitosis- Plant Body - Gametophyte (n) ----------->

---> Archegonium (n) ---> Eggs (n) ---> Antheridium (n) ---> Sperms (n)

Sperm + Egg ---> Zygote (2n) ---> *meiosis* Sporophyte (2n) ---> Sporocyte (2n) -----------> Spore Tetrad

(n) -mitosis- Spores (n) -----------> Plant Body - Gametophyte (n)

“Alternation of Generations”

K: Plantae Div: Hepatophyta

spore tetrads elators

K: Plantae Div: Bryophyta “Mosses”

1. Plant body leafy - mostly upright; no lobes on branches. 2. Rhizoids of multicellualr filaments. 3. Growth of protenema apical. 4. Sporophyte (2n) enclosed within calyptra and pseudoperianth; seta 5. Some have hydroids & leptoids. (no lignin) 6. Branches have buds with distinct tips. 7. Have primitive stomates.

K: Plantae Div: Bryophyta “Mosses”

K: Plantae Div: Bryophyta “Mosses”

K: Plantae Div: Bryophyta “Mosses”

K: Plantae Div: Bryophyta “Mosses”

Gametophores - leafy shootsparaphyses - protective leafy shoots over sexual structure

acrocarpous - sex organs borne at the apices of leafy upright shoots.

pleurocarpous - sex organs born at

the apices of leafy prostrate shoots.

K: Plantae Div: Bryophyta “Mosses”

K: Plantae Div: Bryophyta “Mosses”

Structures of sporophyte: foot (haustorium) - filament - connects capsule to thallus operculum - cap annulus - ring peristome - teeth columbula - sterile central mass sporogeneous tissue - produces sporocytes and

spores (n) calyptra - covers entire capsule tapetum - nutritive tissue apophysis - basal region of capsule; stomates

K: Plantae Div: Bryophyta “Mosses”

Polytrichum

K: Plantae Div: Bryophyta “Mosses”

Funaria

K: Plantae Div: Bryophyta “Mosses”

Mnium

K: Plantae Div: Anthocerotophyta “Hornworts”

1. Thallus growth (like liverworts). 2. Sporophytes look like “horns”. (continuous growth -> 20 cm). 3. No seta - basal region. 4. No protenema. 5. Rhizoids unicellular. 6. Have functioning stomates. 7. Sex organs (antheridium & archegonium sunken in thallus. 8. Usually single plate-like chloroplast in each cell.

K: Plantae Div: Anthocerotophyta “Hornworts”