XVII sec. NOLLIUS Heinrich: NATURAE SANCTUARIUM Quod est Physica Hermetica 1619
Carolus Linnaeus - late 18thC Species Plantarum 1753 Systems Naturae 1767 - (24) major categories of...
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Transcript of Carolus Linnaeus - late 18thC Species Plantarum 1753 Systems Naturae 1767 - (24) major categories of...
Carolus Linnaeus - late 18thC
Species Plantarum 1753
Systems Naturae 1767
- (24) major categories of plants (Divisions)
- (23) vascular (Phanerogams);
- (1) non-vascular & vascular (Cryptogams)
Vascular Plants - The Tracheophytes
• 1. Have specialized cell type for conducting water - tracheids (early xylem tissue). Also has specialized cell type for conducting sugar - seive cells (phloem tissue).
• 2. Lignin in xylem for rigid structural support.
• 3. A branching, independent sporophyte.
Vascular Plants - The Tracheophytes(300 mya)
• Non-seed Tracheophytes - haloid & diploid generations totally independent
• - spores most prominent resting state
Rhyniophyta - the earliest Tracheophytes(extinct by Devonian Period 400 mya)
• 1. Simple vascular system (xylem &
• phloem) in stem.
• 2. “Leaves” flattened scales - no
• vascular tissue.
• 3. No roots - but rhizomes.
• 4. Dichotomous stem branching.
• 5. Aerial branches and sporangia at
• branch tips.
• 6. Spores were in groups of four (?)
• tetrads - indicate meiosis
• plant body - a sporophyte (2n)
• spores - (n) ---> gameophyte (n)-->
• sexual reproduction--> sporophyte (2n)
• (fossil)
Evolution of Leaves• Leaf - a flattened photosynthetic structure emerging from the stem and
possessing true vascular tissue.
• Probably evolved from sterile sporangia.
Evolution of Leaves• Leaf - a flattened photosynthetic structure emerging from the stem and
possessing true vascular tissue.
• Complex leaves arose as photosynthetic tissue developed between complex branching patterns
HeterosporyThe Most Advanced Spore Process
• two types of spores; two types of gametophytes
• heterospory probably evloved several times
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• 1. Leaves small and sessile; no ligule
• at base.
• 2. Stems with aerial branches and
• rhizomes; dichotomous branching.
• 3. Branch roots originate deep within
• main root.
• 4. Mainly perennial.
• 5. Low growing in temperate forest or
• epiphyte in Tropical forest.
• 6. Homosporous.
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• Plectostele - dissected xylem
• with phloem branches in
• between.– Xylem - all tracheids.
– Phloem - all seive cells
• Epidermis - contains stomata.
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• Plectostele -
• Always a layer of parenchyma cells between xylem and phloem.
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• Plectostele - dissected xylem
• with phloem branches in
• between.– Xylem - all tracheids.
– Phloem - all seive cells
– mucilaginous canal
• Epidermis - contains stomata.
• Exarch Stele -
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• A. Exarch Stele -
• B. Mesarch Stele
• C. Endarch Stele
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• Sexual Reproduction:
• sporophyte (2n) ---- meiosis ---->
•
• ------> spores (n) --> gametophyte (n) --> antheridia (n) & archegonia (n)• (homospores)
• antheridium ----> sperms (n)
• -- fertilization --> zygote (2n) --> sporophyte (2n)
• Archegonium ----> egg (n)
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• Sexual Reproduction:
• sporophyte (2n) ---- meiosis ---->
• ------> spores (n) --> gametophyte (n) --> antheridia (n) & archegonia (n)
• antheridium ----> sperms (n)
• -- fertilization --> zygote (2n) --> sporophyte (2n)
• Archegonium ----> egg (n)
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• MALE GAMETOPHYTE:
• Antheridia (n) on crown.• Embedded (like Anthoceratophyta)
• Biflagellated sperms (n)
• FEMALE GAMETOPHYTE looks much the same.
•
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• • strobilus (2n) -• stem with short
• internodes and fertile• appendages
• sporophyll (2n)
• sporangium (2n)
• spores (n)
• • l
K: Plantae Div: LycophytaG: Lycopodium “ground pines”
• gemmae or bulbils (2n)
• (asexual reproduction)
• axial sporophylls
•
•
• g
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• 1. Herbaceous: perennial.
• 2. Ligulate* leaves; microphyllous; spirally or alternately arranged.
• 3. Abundant branching.
• 4. Some vessels* in xylem.
•
• g
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• 1. Herbaceous: perennial.
• 2. Ligulate*leaves; microphyllous; spirally or alternately arranged.
• 3. Abundant branching.
• 4. Some vessels* in xylem.
• 5. Strobilus composed of sporophylls each bearing a single sporangium
• on the adaxial surface.
• 6. Heterosporous* reproduction.
•
• g
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• 6. Heterosporous* reproduction.
• Strobilus (2n) --> microsporophylls (2n) --> microsporangium (2n) -->
• megasporophylls (2n) --> megasporangium (2n) -->
• meiosis
• microsporangium (2n) --> microsporocytes (2n) ---------------> microspores (n)
• megasporangium (2n) --> (4) megasporocytes (2n) ----------> (4) megaspores (n)
•
• g
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• meiosis
• microsporangium (2n) --> microsporocytes (2n) ---------------> microspores (n)
• megasporangium (2n) --> (4) megasporocytes (2n) ----------> (4) megaspores (n)
• --> microspores (n) --> male gametophytes (n), antheridium --> sperms (n)
• --> (4) megaspores (n) --> female gametophytes (n), archegonium --> egg (n)
• dioecious
•
• triradiate
• walls -->
• g
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• fertilization - -> zygote (2n) --> adult sporophyte (2n)
K: Plantae Div: LycophytaG: Selaginella “ground pines”
• fertilization - -> zygote (2n) --> adult sporophyte (2n)
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• 1. Quill-like leaves spirally attached to a corm; microphyllus and ligulate.
• Corm - thickened underground stem. Nodes very close together.
• Lacunae --->
•
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• 1. Quill-like leaves spirally attached to a corm; microphyllus and ligulate.• Corm - thickened underground stem. Nodes very close together. • 2. Each leaf has 4 lacunae; stomata in epidermis. *• 3. Some seive cells lack nucleus at maturity - plasmodesmata with adjacent • cells. • 4. Stem and root protostelic.• 5. Xylem consists of large numbers of parenchyma cells with few tracheids. *• 6. Delicate roots grow from base of corm (rhizophores); stele bound by• well defined endodermis*; have root caps.
• •
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• 7. Heterosporous.• 8. Every leaf of Isoetes is potential a sporophyll; per season - • sterile leaves 1st; then megasporophylls; then microsporophylls.
• --> 1 million microspores; 50 - -> 300 megaspores.
• •
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• Sporangium massive > 7mm.
• Velum - covering over sporangium.
• Trabecula - strands of sterile tissue extending from the sporangial wall.
• Tapetum - innermost layer of the sporangial wall. Indistinguishable.
•
•
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• meiosis (all spores set free)
• microsporangium (2n) ---------> microspores (n) --> male gametophyte (n)
• megasporangium (2n) --------> megaspores (n) --> female gametophyte (n)
• male gametophyte (n) --> antheridium (4 sperms) multiflatelated
• female gametophyte (n) --> archegonium (1 egg)
• *further reduction of
• gametophyte!*
• colorless, saprophytic
•
•
K: Plantae Div: LycophytaG: Isoetes “quillworts”
• male gametophyte (n) --> antheridium (4 sperms)• female gametophyte (n) --> archegonium (1 egg) • *further reduction of • gametophyte!*
• colorless, saprophytic
• no suspensor
• 1 embryo develops• from each gametophyte
• •