ENVS 201 Spring Quarter 2012 Northwest Indian College Welcome to Northwest Plants.

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!