Introduction to Plants Mrs. Foster

Earliest Plants Algae Phytoplankton Lived in the sea

Problems with life on land Drying Out Making Food Reproduction Gravity & Support Getting water & nutrients Solution Waxy cuticle, stomata Formed leaves Develops spores & seeds Bark (cork) & vessels Roots & vessels

Plant Characteristics Multicellular Eukaryotic Photosynthetic 6CO2 + 6H20 + radiant energy C6H12O6 (glucose) + 6O2. Have cell walls made of Cellulose. Not all plants have vascular tissue so they are divided into different phyla

Types of Plants Nonvascular (Bryophytes) Vascular (Tracheophyta) Does not have vascular tissue or true roots leaves, or stems. nonseed plants Vascular (Tracheophyta) vessels for transport and support Have roots, stem, leaves, xylem, and phloem

TRACHEOPHYTES Without seeds With seeds

Nonvascular: The Bryophytes Must grow in moist environments Mosses, Liverworts, Hornworts AVASCULAR = very small Liverworts were the first land plants 500 m.y.a. Used for fuel (peat)

Liverwort / Moss

Non-seed Vascular: The Pteridophytes Club Mosses (Lycophyta) - Leaves produce spores Horsetails (Arthrophyta) Jointed stems Reproduction similar to club moss Ferns (Pterophyta) 400 m.y.a.

Seed Vascular: The Spermatphytes Cycads, Ginkgo Biloba, Gnetophyta, Conifers, Anthophyta 360 million yrs ago during the Paleozoic Era. Conifers= 250 million yrs ago seeds surrounded by a fruit or carried on scales of a cone. Can grow in a wide variety of habitats.

Vascular Plants Vascular tissue that transports food and water Vascular refers to veins Vessels XYLEM = transports water & dissolved minerals from roots to leaves PHLOEM = transports sugars from leaves to rest of plant Spores or seeds for reproduction

Seedless Vascular Plants have vascular system, but do not produce seeds or flowers ex: fern Leaves= fronds Produce spores 3 divisions Lycophyta – club mosses Arthrophyta- horsetails Pterophyta- ferns

Why Make Seeds? Has own food supply Protective coat against harsh conditions Some are designed for travel to new areas

Vascular Seed Plants Seed—protective structure where embryonic plant can be stored until conditions are favorable for growth. Two types of seed plants Gymnosperms (4 phyla) Angiosperms (1 large phylum)

Gymnosperms Gymno = “naked” Sperm = “seed” First plants to produce seeds No flowers, No fruit Seeds are not protected by a fruit Examples: Ginkgo biloba Conifers—plants with seeds inside cones and needle-like leaves Pines, firs, cedars, redwoods

Coniferophyta (largest group of gymnosperms) Needle or scale-like leaves Bear seeds in woody cones Can live in very cold climates Most are evergreens Have wood Made of thick-walled vessels

Angiosperms Angio – “flower” Sperm – “seed” Extremely diverse All have seeds enclosed in fruit Produce fruits with 1 or more seeds Fruit is the ripened ovary of flower Fruit aid in seed dispersal Examples: maple trees, apple trees, wildflowers, herbs, azaleas, grass, oak trees, poplar trees

Flowers Pistils = female reproductive structures Stamens = male reproductive structures Complete flowers Have petals & sepals Have male and female parts Incomplete flowers = missing one or more parts

Two types of Angiosperms Monocot Ex: corn, grass Dicot Ex. trees, shrubs, sunflowers , most flowers

Types of Angiosperms Monocots mono = “one” cot = “seed leaf” Approx. 60,000 species Flowers = multiples of 3 Leaf veins parallel Dicots di = “two” cot = “seed leaf” Approx. 170,000 species Flowers = multiples of 4 or 5 Leaf veins branching