plantking

PLANT TAXONOMY

I. THALLOPHYTES - plants with no vascular tissue
o surrounded by water and nutrients which can diffuse in through osmosis, no need for roots
o O2 diffuses out and CO2 diffuses in through thin blades, no need for stomates
o alga is “weightless” in water or larger kelps have air bladders, no need for woody stem
o sugar is manufactured in all blades that sway to catch sunlight, no need for transport system
o some algaes have special pigments to absorb a greater range of light waves, allowing them to grow well in low light   conditions
o spores and gametes are spread by water currents, no need for seeds to protect an embryo from drying out or   carrying extra nutrients
o all have a life cycle consisting of an alternation of generations, with separate male & femalegametophyte and   sporophyte plants
A. CHLOROPHYTA = (green algae)
1. Morphology
   a. unicellular, filamentous, colonial, multicellular
    1) the most diverse form of algae
    2) include common freshwater algaes like Spirogyra, Ulothrix, Volvox (colonial), and marine Ulva, Codium (     dead-man’s fingers)
   b. Contain chlorophylls a + b (same as a true land plant)
   c. Contains beta-carotene and xanthophyll accessory pigments (like true land plants)
   c. Stores their energy as true starch (easily digestible by an aquatic or terrestrial herbivore)
   d. Has cellulose in its cell walls (like true land plants)
2. Taxonomy
   a. 50% are freshwater forms
   b. Contains the smallest number of species
   c. BELIEVED TO BE THE ANCESTOR OF TRUE LAND PLANTS
3. Reproduction
   a. Asexual - Diploid (2n) sporophyte plants divide by binary fission
    b. Sexual - when the currents, water temp, nutrient & light levels are optimum, Diploid (2n) sporophyte plants     produce flagellated haploid (n) spores through meiosis. Spores settle and grow into haploid gametophytes     and, undergo sexual reproduction by making haploid gametes by mitosis. Gametes may fuse through     syngamy, become diploid (2n) zygotes and settle down to grow into new sporophyte plants to continue the     cycle.
4. Commercial uses
   a. As a wrap for sushi; dried and sprinkled in salads, Asian dishes; filler for animal feed
B. PHAEOPHYTA = (brown algae)
1. Morphology
   a. filamentous, multicellular forms
    1) the largest and fastest growing form of algae
    2) mainly marine species, includes “seaweeds” like Dictyota and Zonaria and Kelp (larger seaweeds      needing pneumatocysts (air bladders) to float the fronds to the surface for photosynthesis) like      Macrocystis, Sargassum and Egregia
   b. Contain chlorophylls a + c (absorbs more green + blue wave lengths of light, can grow deeper)
   c. Contains fucoxanthin accessory pigment (reflects yellow-brown wavelengths of light)
   c. Stores their energy as laminarian starch (indigestible to terrestrial animals)
   d. Has algin in its cell walls (a mucous-like starch, makes kelp unpalatable to eat)
2. Taxonomy
   a. More species than green algae, most species are marine
3. Reproduction
   a. Asexual - Large, diploid (2n) sporophyte plants have specialized sporophyll blades at their base which     produce flagellated haploid (n) spores meiosis. Spores settle and grow into tiny haploid gametophytes,     sometimes no more than a “fuzz” 2mm high, covering exposed rocks.
    b. Sexual - when the currents, water temp, nutrient & light levels are optimum, the tiny gametophytes undergo     sexual reproduction by making haploid gametes through mitosis. Gametes may fuse through syngamy,     become diploid (2n) zygotes and settle down to grow into new, sporophyte plants to continue the cycle.
4. Commercial uses
   a. Most common emulsifier found in jellies, toothpaste, salad dressings - anything that needs “thickening” or     needs to keep large particles suspended in a liquid. Mixed with animal feed (no more than 10% or their hair     falls out!) as “roughage.”

C. RHODOPHYTA = (red algae)
1. Morphology
   a. filamentous, multicellular
    1) the most advanced and deepest growing form of algae, almost all marine. Contains MANY more species      in comparison with Chlorophyta or Phaeophyta
    2) include common intertidal algaes like Rhodophyta, Plocamium, the calcareous algaes, and      Pterocladia
   b. Contain chlorophylls a + d (same as a true land plant)
   c. Contains phycoerythrins - accessory pigments that allow them to absorb more off the blue end of the     spectrum, reflecting red and allowing reds to grow in very deep waters.
   d. Stores their energy as Floridean starch (indigestible or toxic to most aquatic & land animals)
   e. Has agar in its cell walls (like true land plants)
   f.   Some forms are CYNOCYTIC (many nuclei in the same thallus - body of the plant)
2. Taxonomy
   a. Almost all are marine
   b. Contains the largest number of species which live from the high tide zone to 200 m deep.
   c. Many intertidal red algaes incorporate CaCo3 into their tissues (calcium) to help them withstand the breaking     waves.
3. Reproduction
   a. Asexual - Uniquely shaped, diploid (2n) sporophyte plants have specialized tetrasporangia at their tips or     along the axis of the plant produces flagellated haploid (n) tetraspores through meiosis. Spores settle and     grow into identifiably-different haploid gametophytes, often as large as the sporophytes.
    b. Sexual - when the currents, water temp, nutrient & light levels are optimum, the tiny gametophytes undergo     sexual reproduction by making haploid gametes through mitosis. Separate male plants release sperm out     their antheridium (“wanna-be anther) which swim to the female’s oogonium (egg receptacle) Gametes fuse     inside through syngamy, diploid (2n) zygotes are released and settle down to grow into new, large     sporophyte plants to continue the cycle.
4. Commercial uses
   a. As a wrap for sushi (Nori); biggest use is acting as the substrate for bacterial plates. Can be sterilized,     additives blended uniformly throughout the medium. Used as the major emulsifier in gum (as     “carrageenan,”) milk (keeps milk and cream from separating - homogenizing), makes ice cream smooth, the     “gel” on gel caps, etc. MANY antibiotics come from red algae (erythromycin), several blood pressure     medications, clotting factors.

KINGDOM PLANTAE
THALLOPHYTE LAND PLANTS

I. Bryophyta (mosses, liverworts, hornworts)
A. Morphology:
1. no roots: has rhyzoids for aftachment
2. Contains chlorophylls a + b, beta-carotene, xanthophyll
3. Has no stomates, only air pores for gas exchange
4. non-vascular (water & nutrients diffuse throughout tissues)
5. close-to-ground, small, thin blades (diffijsion only occurs over short distances)
B. Reproduction:
1. Asexual: in liverworts, can make 'gemma' (wort-like lesions on surface) through mitosis; also, through     fragmentation
2. Sexual: alternation of generations
   a) gametophyte is the dominant stage
   b) sporophyte is non-photosynthetic, feeds off the gametophyte like a parasite-
   c) sperm formed in the Antheridium (maie structure) are biflageilate
   d) egg formed in the Archogonium is fertilized by sperm who swam into the structure during a rain.
3. Habitat : live in moist, shady places
4. Importance:
   a) Economically, sphagnum moss is sold widely fbr floral arrangements; mosses are used in landscaping.
   b) Major primary producers in tundra biomes and by riverbeds.
   c) Moss comprises peat, used for fuel in some areas
   d) Nafive peoples use moss to pack wounds, as diapers, etc.

TRACHEOPHYTE PLANTS

1. TRACHEOPHYTES - plants with vascular tissue
o need roots to bring in water and nutrients by osmosis
o has stomates which open & close to let 02 S out and C02 in, usually open at night
o for perennial plants, need woody stems & bark for support & protection from predators o sugar is manufactured in leaves, transported through the plant by phloem
o embryo carried in seeds to prevent drying out: often carry extra nutrients as well
o male gametes carried as pollen, with wind or animal dispersal
o all have a life cycle consisting of an alternation of generations, with male & female gametophytes carried within a sporophyte's cone or flower

A. Psilophyta (whisk ferns)
1. Morphology
   a. Primitive tracheophyte, has microphyll leaves (only one vascular bundle)
    1) has roots, leaves with stoma
   b. Has S'02 as a strengthening agent in cell walls
2. Reproduction
   a. Asexual - Large, diploid (2n) sporophyte plants produce bufton-like haploid (n) spores via meiosis.   Spores     settle and grow into haploid gametophytes
   b. Sexual - the gametophytes undergo sexual reproduction by making haploid gametes,
    mitosis. Flagellated sperm produced by male gametophytes swim into female archegonia, fuse through     syngamy, become diploid (2n) zygotes and settle down to grow into new sporophyte plants to continue the     cycle.
3. Importance
   a. a major plant of the Carboniferous era, giving us petroleum.
   b. native peoples use the stick-like leaves as whisk brooms

B. Lycophyta (club mosses)
1. Morphology
   a. Primitive tracheophyte, has microphyll leaves (only one vascular bundle)
    1) a ground cover in moist areas
2. Reproduction
   a. Same as Psilophyta except sporophylis bunch into a "cone"
3. Importance
   a. a major plant of the Carboniferous era, giving us petroleum.
   b. used by florists and landscape architects

C. Sphenophyta (horsetails)
1. Morphology
   a. Primitive tracheophyte, has microphyll leaves in whorls
    1) ribbed, jointed stems topped by cone-like sporangium
2. Reproduction
   a. Same as Psilophyta except spores are multi-flagellate
3. Importance
   a. a major plant of the Carboniferous era, giving us petroleum.
   b. used for landscaping around ponds, sporangium used as a pot scrubber

D. Pterophyta (Ferns: WAS Class:Filicinae)
1. Morphology
   a. large, feathery megaphyll leaves bear sporangia on undersides
    1) "fiddle-neck" fronds covered with silvery hairs poke up from underground stems called rhizomes
2. Reproduction
   a. Asexual: sporophyll fronds contain SORI in bunches on their undersides
   b. Sexual: separate gametophyte is tiny, heart-shaped, with both sexes on same plant
   c. Sperm from Antheridium swim to Archegonium, fuse, sporophyte grows from gametophyte
3. Importance
   a. a major plant of the Carboniferous era, giving us petroleum.
   b. Still dominant in moist shady places

GYMNOSPERMS- Naked seeds, wind pollinated, long lived, resistant to diseases & pests

A. Coniferophyta (Conifers)
1 .Morphology
   a. Megaphyll leaves, often reduced to scales or needles
   b. contain veins w/water-carrying TRACHEID cells + sugar carrying SIEVE CELLS
   c. has STOMATA, RESIN DUCTS to heal wounds
   d. can be small to giant (largest, tallest, widest, and oldest plants alive)
2. Reproduction
   a. "Naked" seeds coming from cones; seed=embryo, nutritive layer, protective coat;
   b. embryo in ovule, sperm carried in pollen
   c. NO flagella, gametophyte=DEPENDENT; comes from MEGASPORES OR MICROSPORES;
3. Importance
   a. commercially valuable wood
   b. tannic acid tans hides, kills competing plants
   c. some pines (like the yew tree) contain strong anti-cancer agents (TAXOL kills breast cancer)

B. Gingophyta (Gingkos) *only one species leftill
1 .Morphology:
   a. LARGE fan-shaped Megaphyll leaves that turn yellow and drop off during winter
   b. spreading shade tree, ultra-resistant to smog, pests, & disease
2. Reproduction
   a. Separate male & female trees (MONACIOUS)
   b. females grow nut-like cones that STINK horribly
3. Importance
   a. Males planted as shade trees in industrialized cities throughout the world

C. Cycadophyta (Cycads)
1 .Morphology:
   a. LARGE fern-like Megaphyll fronds that drop off one by one like palms
   b. extremely slow-groyang
2. Reproduction
   a. Separate male & female trees (MONACIOUS)
3. Importance
   a. Used in office & home decorating (hardly grow in height); large female cone is ground, leached in water for 9     days (extremely toxic otherwise) and used as flour for tortillas in Micronesia.

ANGIOSPERMS: flowers, seeds with fruits, many have poilinators, secondary woody growth Ovary inside a carpel, pollen in      anthers

A. Anthophyta (flowering plants)
1. Class: Monocotyledonacae (monocots)
   a. Morphology
    1) Scaftered vascular bundles
    2) Flower parts usually in 3's
    3) pollen w/ one furrow
    4) major veins in leaves parallel
    5) Ovary usually superior to petals
    6) Root growth is fibrous
    7) Newly emerged plantlet has ONE cotyledon (embryonic leaf)
    8) Nutrition for embryo carried as endosperm within a seed
   b. Reproduction
    1) Gametophytes reduced to a few cells within ovules or pollen grain
    2) Pollen reaches stigma (sticky top of carpel), grows pollen tubes, divides sperm cells once before      reaching ovuole and fertilizing egg and polar nuclei (which becomes 3N endosperm to feed the       developing embryo
    3) Meiosis and then mitosis occurs in each ovuole, creating 6 haploid cells and one dikaryotic cell in the      middle (polar nuclei). Only the egg and polar nuclei are fertilized, the extra cells are reabsorbed.
   c. Importance
    1) contains most food grains, grasses, bulbs. Palm is the only monocot tree.

2. Class: Dicotyledonacae (dicots)
   a. Morphology
    1) Vascular bundles in a ring
    2) Flower parts in 4's or 5's
    3) pollen w/2 furrows
    4) major veins in leaves net-like
    5) Ovary usually inferior to petals
    6) Root growth is a tap root
    7) Newly emerged plantlet has TWO cotyledons (embryonic leaf)
    8) Nutrition for embryo carried in the cotyledons
   b. Reproduction - same as monocots
   c. Importance
    1) contains the greatest variety of species, herbs, flowers, almost all trees (hardwood). Many drugs come      from dicots.

TRENDS IN VASCULAR PLANTS

I. The Root
A. Developed to take the place of hyphae or holdfasts
B. Used for water and mineral absorption (diffusion directly thrOLtgh plant body now limited to protec+water loss)
C. Used for anchoring in soil

II. The Leaf
A. A thick cuticle 1-Ryer developed to protect the plant from dessication
B. Still the same site for photosynthsis
C. Developed pores (stomata) for gas + water exchange
D. Developed 2 distinct forms of leaves
1. Microphylls - a single strand of vascular tissue
2. Megaphylls - complex system of veins

III. Vascular System
A. Developed XYLEM for the transport of nutrients and water UP from the roots
B. Developed F'HLOEM for the transport of newly-made food DOWN from the leaves

IV. Gametophyte Reduction
A. Reduced the size and +unction of gametophyte forms
1. from a small but independent existence to a MICROSCOPIC and TOTALLY DEPENDENT existence

V. Separate the Reproductive Cycle
A. Develop SEPARATE types of gametophyte plants
1. one produces the archogonium
2. one produces the antheridia

VT. The Seed
A. Replace the archogonium and antheridium with the seed
B. Develop a protected, enclosed seed from a "naked", Ltnprotected seed (gymnosperms)
EVOLUTION IN CHLOROPHYTA

Green algae believed to be the ancestors of Plant Kingdom
A. They have the same chlorophylls and pigments as plants
a. b + beta-carotene - no other algae group HAS)
B. They store food only as STARCH.
C. Many have cellulose-containing cell walls
They can be considered a bridge between unicellular and multicellular forms