Kingdom Plantae
multicellular, autotrophic, vascular and nonvascular, sexual and asexual
reproduction, alternation of generation
Kinds of Plants
• Bryophytes=Mosses-non-vascular
• Pteridophytes=Ferns- vascular
• Coniferophytes=Gymnosperm=Conifers-cone bearing plants
• Anthophyta=Angiosperm=Flowering plants, may be monocots or dicots
Parts of simple leaf
tip- the terminal point of the leaf. blade-the flattened, green, expanded portion of a leaf. margin- edge of a leaf.midrib-the most prominent central vein in a leaf.
lateral veins-secondary veins in a leaf. petiole-the leaf stalk (connects blade to stem). stipules-leaf-like appendages (at the base of petiole of some leaves).
Parts of compound leaf
leaflet- secondary leaf of a compound leaf. rachis- an extension of the petiole bearing leaflets. petiolule-the leaflet stalk. petiole-the leaf stalk lateral veins-secondary veins in a leaf. stipules-leaf-like appendages (at the base of petiole of some leaves).
Seeds—fertilized eggs
• Naked--Gymnosperm– pines
• Covered--Angiosperms– Covered by dry of fleshy fruit, contains seeds
Leaf arrangement
Fruits
Roots and stems we eat
Flowers we eat
List at least 5 practical human uses for roots
• Food storage – sugar, beets, turnip, rutabagas, parsnip, radish, carrot
• Spices – Sassafras, sarsaparilla, licorice,
• Dyes – reds, browns, coffee bean
• Drugs – gentian, reserpine (tranquilizer)
• Insecticide – rotenone
practical human uses for wood and stems
• In a living tree, 50% of the wood weight comes from water content. – Dry weight is composed of 60-75% cellulose and 15-25% lignin.
• Density and Durability are two of the most important characteristics in commercial wood.
• Sawing – Radially cut (quartersawed) boards show the annual rings in a side view. – Tangentially cut (plain-sawed) boards show annual rings as irregular bands of
light and dark streaks. • Knots
– Bases of lost branches covered by new annual rings produced by the cambium of the trunk.
– Found in greater concentration in older parts of the log, towards the center. • Wood Products
– About half of US and Canadian wood production is used as lumber, primarily for construction.
• Veneer - Thin sheet of desirable wood glued to cheaper lumber. – Second most extensive use of wood is pulp. – In developing countries, approximately half of cut timber is used for fuel.
• Less than 10% in US and Canada
leaves
• Human Relevance of Leaves• Landscaping • Food • Dyes • Ropes and Twine • Drugs
– Tobacco – Marijuana
• Insecticides • Waxes
Dicots versus Monocots Seeds
Dicots Monocots
•Two cotyledons •Flower parts in fours or fives •Leaves with distinct vein network •Vascular cambium present •Vascular bundles in ring •Pollen grain with three apertures
•One cotyledon •Flower parts in threes •Leaves with parallel primary veins. •Vascular cambium absent •Vascular bundles scattered •Pollen grain with one aperture
Distinguish between a fruit and vegetable
• Fruit is an ovary and its accessory parts that have developed and matured. – Usually contains seeds. – All fruits develop from flower ovaries and accordingly
are found exclusively in flowering plants.
• Vegetables consist of leaves, leaf petioles, specialized leaves, stems, roots, flowers and their peduncles, flower buds or other parts of the plant
Conditions necessary for germination to take place
• Water, oxygen, temperature
• In some cases– Light—small seeds planted at soil surface, as
planted too deep—do not germinate– Extreme conditions
• Acids in digestive tract of animals• Very cold environment
Asexual reproduction in plants
• Clones
• Vegetative reproduction– Runners (stolens)--strawberries– Rhizomes—underground stems-sugar cane,
ferns– Bulbs-garlic, tulips, daylilies, onions– Tubers- Potato, caladium
• Human Propagation
What is propagation?
• When people grow new plants using plant parts such as plant cuttings of roots, stems, leaves.
• Other methods – Layering– Grafting– Tissue Culture
Seed Dispersal
• Reason---get away from parents! Competition for same resources (water and minerals, sunlight etc.)
• Methods:– Winds– Animals (carried on clothing, fur, inside and deposited
somewhere else)– Water– Forcible discharge– Gravity
Plant Hormones????? not just for humans
• Chemical messengers affect plant’s abilities to respond to the environmental conditions
• These hormones can stimulate or inhibit growth, fruit ripening, cell mitosis, bring dormancy
• Five major groups include: Auxins (including 2, 4-D/ Agent Orange), gibberellins, ethylene, cytokinins, and abscisic acid
• Growth regulators – as in growth retardants –chemicals that prevent plant growth—so we do not have to mow or cut back as often
Tropisms????
• A response in which a plant grows either toward or away from an environmental stimulus.
• Examples include– Phototropism—grow toward the light—stems– Thigmotropism– response to touching a solid object—
as in climbing and attaching as they grow upward– Gravitropism– root usually grows toward (positive),
and stem away (neg.)– Chemotropism– plant growth in response to chemical
—such as pollen tube growth following pollination, taking pollen to the egg in ovary
Nastic movements
• Plant movements in response to environmental stimuli
• Examples:– Touch me not plant—closes up when touched– Folding leaves to reduce insect invasion,
reduce water loss, daily day and night cycles (flower clock)
Photoperiodism
• Plants response to to changes in the length of days and nights
• Some plants will not flower until the hours are right!!– Short day plants– Long day plants– Day neutral plants
Nurseries and Farmers
Can adjust the flower clocks to get plants to bloom at a desired time of the year---– Poinsettia for Christmas time– Easter lilies for the spring and Easter season
Also
– following a low-temperature stimulation
some plants produce healthy plants and an earlier crop.