Plant Anatomy and Physiology Just the Concepts

PLANT CLASSIFICATION

Objectives Explain systems used to classify plants; Compare and contrast the hierarchical classification of agricultural plants; and Classify plants according to life cycles, plant use, and status as monocot or dicot.

Classification Systems What are some ways that we could classify plants?

Classification Systems Taxonomy: the science of classification To classify into ordered categories

Classification Systems Why Classify? Carolus Linnaeus ( ) Swedish botanist / physician that collected plants for their curative properties needed to organize his collection. Contributed to the development of our modern system of taxonomy. Developed binomial nomenclature, a two-word naming system still used today. Carl

Classification Systems Botanical Classification D K P C O F G S Domain Kingdom Phylum Class Order Family Genus Species

Classification Systems

Mode of Reproduction Sexual Develop from a seed or spore after the union of male and female gametes Gametes: Sex cells Asexual Reproduce by vegetative means without sexual gametes

Classification Systems Mode of Pollination Naturally self-pollinated Pollen and embryo sac are produced in the same floral structure or different flowers on the same plant Naturally cross-pollinated Pollen transferred from one flower to another flower of a different plant Both self- and cross-pollinated Largely self-pollinated, but a some cross-pollination will occur

Classification Systems Life Cycle Annual Plants germinate, grow, flower, produce seed, and die all in one season Biennial Requires two growing seasons to complete its life cycle The first accumulating food reserves; the second producing reproductive parts Perennial Plant that lives indefinitely; produces seeds year after year

Classification Systems Growth Habit Herbs Succulent plants with self-supporting stems Vines Herbaceous climbing, or twining plants without self-supporting stems Lianas Woody climbing or twining plants that require other plants for vertical support Shrubs Small tree-like plants generally less than 15 feet tall; produce several trunks from the base Trees Plants with continuous growth and a large development of woody tissue; single, distinct stem; more than 15 feet tall

Classification Systems Leaf Retention Evergreen Maintain their leaves throughout the year Deciduous Naturally shed their leaves annually for extended periods

Classification Systems Ecological Adaptation or Habitat Epiphyte Grow above ground on another plant for vertical support; not a parasite Halophyte Can grow in high salt conditions Hydrophyte (Aquatic) Grow in water or in waterlogged soil Lithophyte Grow in rocks or rocky terrain Mesophyte Adapted to growing in moderate conditions (most of the plants that we know) Parasite Grows on another plant and takes its nourishment from that plant Saprophyte Grow in decaying matter and have no green tissue Sciophyte Adapted to low light conditions Terrestrial Grows on land with roots under ground absorbing water and a shoot above ground (most of the plants that we know Xerophyte Adapted to grow in areas with little or no water

Classification Systems Flowering vs. Non-Flowering Flowering plants produce seeds Seed Parts (Cotyledons) Monocot Dicot

Classification Systems Monocot Embryo with one Cotyledon Pollen with one furrow or pore Flower parts in multiples of three Major leaf veins are parallel Vascular bundles are scattered in the stem Roots are adventitious Dicot Embryo with two cotyledons Pollen with three furrows or pores Flower parts in multiples of four or five Major leaf veins are netted Vascular bindles are a ring in the stem Roots develop from a radicle

Agricultural Classification Crops vs. Weeds Crop A useful plant grown for a specific purpose Used by humans directly or indirectly, raw or processed Intentionally grown and managed Weed Any plant growing where it is not wanted Competes with the intended plant for space, light, nutrients, and water

Agricultural Classification Agronomic Crops vs. Horticultural Crops Agronomic (Field Crops) Mostly annual, herbaceous plants grown under extensive or large-scale culture Usually dried and processed prior to use Horticulture crops Annual and perennial plants grown under intensive culture Intensive: large input of capitol, labor, and technology per acre High moisture content, spoil quickly Used for food, medicine, beauty

Agricultural Classification Could some plants be classified in several groups? Which ones?

Agricultural Classification We have got to have some order We base most classifications on Primary Use rather than on the other minor uses

Agricultural Classification Food Crops Non-Food Crops Staple Crops Grain Crops Legume Seed Crops Root & Tuber Crops Oil Seed Crops Sugar Crops Beverage Crops Rubber Crops Latex & Gum Crops Dye & Tannin Crops Fiber Crops Pasture & Forage Crops Biofuel Crops Olericulture Crops Spice Crops Essential Oil Crops Ornamental Crops Biocidal Crops Industrial Crops Plantation Crops