ENVS 201 Spring Quarter 2012
Northwest Indian College
Welcome to Northwest Plants
Plant Parts
stems
roots
leaves
flowers
fruits
seeds
vegetative organs:
reproductive components:
Today:Flowers
Flower Features & Functions
involved in sexual reproduction of flowering plants (angiosperms)
produce fruits & seeds (following pollination and fertilization)
vary little; primary basis for identification & classification
may be self-pollinating or pollinated by various organisms
lily magnolia (Magnolia soulangiana) flower, l.s. (magnoliid)
Flower Components—Fertile, Male
stamen - male reproductive structure
filament - slender stalk-like structure
anther - region of pollen sacs
Flower Components—Fertile, Female
pistil - female reproductive structure
stigma - region at tip of style that receives pollen
style - stalk of the pistil
ovary - swollen base of pistil, becomes fruit
snapdragon (Antirrhinum majus) inflorescence
snapdragon (Antirrhinum majus) flower, l.s. (eudicot)
Flower Components—Sterile (Auxiliary
Structures)
petal - one of the elements of the whorl inside the sepals (may attract pollinators)
sepal - one of the elements in the outermost whorl
tepal - petal and sepal, if indistinguishable from one another (e.g., lilies)receptacle - base where petals, etc. attached
lily (Lilium) flower
lily (Lilium) life cycle (monocot)
Other Flower Terms
complete - flower with all four floral parts (sepals, petals, stamens & pistils)incomplete - flower lacking one or more partsperfect - flower with male & female parts; pollen & ovules produced
imperfect - flower lacking stamens or pistils; pollen or ovules not produced
Flower Terms (continued)
peduncle - stalk of an inflorescence or of a solitary flowerpedicel - stalk of an individual flower in an inflorescence (or of a grass spikelet)
Flower Terms (continued)
dioecious, dioicous -”two houses,” plant species with separate male & female plants; male & female flowers on separate plants (imperfect, unisexual flowers)
monoecious -”one house” (with two rooms), plant species with both male & female flowers on same plant; both types of imperfect, unisexual flowers on same plant
Flower Terms (continued)
regular (syn. actinomorphic) - flowers which are radially symmetrical (capable of being bisected into identical halves from any longitudinal cut (e.g., lily)irregular (syn. zygoomorphic) - flowers which are bilaterally symmetrical, only capable of being bisected in one plane to produce equal halves (e.g., snapdragon)
Ovary Positionepigynous, epigyny - describes a flower which has an inferior ovary, with the sepals, petals and stamens attached at or above the top of the ovary
perigynous, perigyny - borne around the gynoecium; floral parts (calyx, corolla and stamens) are attached to the edge of a cup-shaped hypanthium
hypogynous, hypogeny - flower parts attached below the base of the ovary and free from it; flowers with this arrangement have a superior ovary
Flowers & Inflorescences
solitary - plant with a single flower per stalk
inflorescence - flowers grouped together in clusters of more than one flower
Questions & Comments?
Flowersarecool.
Hy’shqe!
