IMPORTANCE OF PLANTS

Importance of Plants Oxygen Food/feed Medicine – Absorb Carbon Dioxide Decoration (Aesthetic)

PLANT LIFE CYCLES

Plant Life Cycle Annual – Goes from seed to producing seed in one growing season – Ex. Corn, beans

Summer Annuals Summer annuals germinate in the spring. Summer annuals produce leaves, flowers, and seed before dying during the summer or fall. – Many crops and garden plants are annuals. – Corn, soybeans, rice, wheat, potatoes, and tomatoes – Petunias, impatiens, marigolds, and zinnias – Ragweed, pigweed, lambsquarter, crabgrass Photo, courtesy USDA Peggy Greb

Winter Annuals The seed of a winter annual germinates in the fall. The immature plant overwinters as a compact rosette. Once the plant has received a sufficient period of cold treatment, it bolts.

Winter Annuals Bolting is a process in which the stem of a plant rapidly elongates at the time of flowering. – Flowers then develop, seeds are set, and the plant dies. – Winter wheat

Plant Life Cycle Biennial – Goes from seed to producing seed in two growing seasons – 1 st year – vegetative growth – 2 nd year – vegetative and flower growth – Ex. Carrot, burdock

Biennials Biennials are plants that normally require two growing seasons to produce flowers and seed before dying. – First growing season: biennials grow vegetatively. – Next: plants go dormant and rest until the Spring – Winter: receive a required cold treatment – Growth is resumed in the spring of the 2 nd season. – The plants bolt, flower, produce seed, and die. – Hollyhock, Sweet William, parsley, beets, and carrots

Plant Life Cycle Perennial – Lives more than two growing seasons – Ex. Trees, shrubs

Perennials A perennial is a plant that has a life cycle of more than two growing seasons. – May take perennial plants a few years to many years to reach reproductive maturity. – Perennials may be woody like trees and shrubs or herbaceous.

On the flip chart(s) – create a Venn-Diagram to compare and contrast the three types of plant life cycles

MAJOR PLANT STRUCTURES

Major Plant Structures Flower – Attracts insects for pollination Fruit – Seed-carrying structure

Major Plant Structures Seeds – Produces new plants Leaves – Produces food/sugars

Major Plant Structures Stem – Supports the plant – Transports water, nutrients and food/sugar Roots – Anchors plant – Absorbs water and nutrients – Stores food