Kingdom Plantae Plants
Evolution of Plants • Three adaptations allowed plants to thrive on land: • Ability to prevent water loss • Ability to reproduce in the absence of water • Ability to absorb and transport nutrients
Preventing Water Loss • Cuticle – a waxy protective covering on plants that prevent water loss. • Stomata – small openings that allow the exchange of oxygen and carbon dioxide
Reproduction • Spores- reproductive cell that is surrounded by a hard outer wall to prevent drying out. • Allows wide dispersal of plant species • Seeds- an embryo surrounded by a protective coat.
Nutrients • Plants evolved vascular tissue to transport water and disolved substances from one part of the plant to another. • More Information To Come
Classification of Plants • Plants can be divided in two groups based on the presence of vascular tissue. • Nonvascular Plants • Vascular Plants
Nonvascular Plants • Lacks true vascular tissue • Lacks true roots • Lacks true stems • Lacks true leaves • Ex. Mosses, Liverworts, and Hornworts
Bryophytes • Most primitive type of plants. • Need water to reproduce – sperm must swim through water to egg. • 16,600 species • Grow on land near streams and rivers.
Vascular Plants • Have vascular tissue • Have true roots • Have true stems • Have true leaves
Vascular Plants • Can be further divided into two groups: • Seedless Plants • Ex. Ferns, whisk ferns, club mosses, horsetails • Seed Plants • Ex. Cycads, ginkgoes, conifers, flowering plants
Seedless Plants • Whisk Ferns – no roots or stems, reproductive structures on ends of forked branches • Club Mosses – evergreens that produce spores in cones, have roots • Horsetails – jointed stems • Ferns – have underground stem, spores on underside of leaves • Fiddleheads- coiled new leaves
Vascular Seed Plants • Young plants are called – SEEDLINGS • Two main groups: • Angiosperms • Gymnosperms
Gymnosperms • Bear seeds in cones • Cycads – palm or fernlike leaves, different sexes, cones with seeds • Ginkgoes – fan shaped leaves, different sexes, large fleshy seeds • Conifers – needlelike leaves, cones with seeds
Angiosperms • Flowering plants • Have seed, flower, and fruit • Herbaceous – showy flowers • Shrubs- rose bushes • Vines – grape plants • Trees – oaks, aspen, and birch • Grasses
Monocots • One cotyledon (seed leaf) • Long leaves with parallel venation • Flower parts come in multiples of three • Vascular bundles are scattered • Fibrous root system (discuss later) • Ex. Lilies, irises, orchids, tulips, bananas, pineapples, coconut, grasses
Dicots • Two cotyledons • Broader leaves with net-like venation • Flower parts come in fours or fives • Vascular bundles arranged in a circle • Taproot System (Discuss later) • Ex. Beans, lettuce, oaks, maples, elms, roses, carnations, cactuses.