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!