Using Plant Parts & Life Cycles to Classify Plants Plant Classification Using Plant Parts & Life Cycles to Classify Plants

Learning Objectives List and explain the common plant parts and life cycles used when classifying plants. Classify plants according to their life cycle: perennial, annual, biennial. Explain how to identify plants by using a Dichotomous key.

Using Plant Parts to Identify Plants People involved in the horticulture industry look for the following characteristics in plants to correctly identify them: Vascular or Non Vascular Plant Types of Stems Types of Leaves Flowering Plants

Vascular vs. Non Vascular Vascular Plants They have a system that can circulate fluids. Two types: Plants which produce flowers are called angiosperms (class) EX: Roses Plants which don’t produce flowers, know as vascular plants with spores, are call Gymnosperms (class) The number of petals on a flower is also used to classify plants EX: Ferns Non Vascular Plants These plants cannot absorb rainwater through their stems and leaves but must absorb it from the environment that surrounds them. EX: Mosses and Fresh Water Algae

Types of Stems Herbaceous Plants: have stems that are soft and not woody herbs, vines, grass Woody plants: are self supporting trees, shrubs which produce wood

Types of Leaves Deciduous plants Evergreens Type of leaf: Leafless during part of the year. Evergreens Keep their leaves year round Type of leaf: Arrangement Venation Margin Simple or Compound Texture Variegation

Plant Phases Vegetative phase: Reproductive phase Dormancy: when a seed germinates and produces seed, roots, stems, and leaves. Reproductive phase flowers and produces fruit. Dormancy: inactive or slowed growth (cold, drought, or short daylight)

Life Cycles Plants can also be identified by their life cycle. Three types Annuals: germinate, grow, flower, and produce seed in one growing season EX: petunias, marigolds, tomatoes Biennials: complete their life cycle in 2 years EX: cabbage, beets Perennials: may be herbaceous or woody and live for more than 2 seasons EX: strawberries, asparagus, most trees

Dichotomous Key The method for determining the identity of a plant. Dichotomous means: Divided into two parts The key goes through a series of questions that leads the person to the correct name of the item. At teach step of the process of using the key, the person is given two choices: each alternative leads to another question until the item is identified. Example of Identifying a Tree: Questions may be: Are the leaves flat or needle-like? If the answer was needle like them the next questions may be: Are the needles in a bunch or are they spread along the branch? Eventually, when enough questions have been answered, the identity of the tree is revealed.

Dichotomous Key Examples

Exit Ticket! List the two types of plants used in classification. What is the difference between an angiosperm and gymnosperm? How are stems used to classify plants? List three ways to classify plants by using their leaves. ________cycle germinates, grows, flowers and produces seeds in one growing season. ________cycle classify’s plants living more than two growing seasons. ________cycle plants complete their life cycle in two years. What is a dichotomous key?