Plant anatomy

Reproductive parts

Flower

Flower - Sterile Parts

1. Peduncle = flower stalk

• receptacle (swollen tip of peduncle; flower parts attached here)

2. Sepals

• sepals collectively known as the calyx

3. Petals

• petals collectively known as the corolla

 

Flower - Fertile Parts

Stamens – male reproductive organs, collectively called androecium

a. Filament

b. Anther

• pollen grains develop here

 

Flower - Fertile Parts

Pistil (Carpel) = female reproductive organ, collectively called gynoecium

1) Stigma

2) Style

3) Ovary, contains ovules

a) Ovules mature into seeds

b) Ovary matures into fruit

Flower parts

•Not all flowers have all parts

•Four basic parts are:

–Pistils (Gynoecium)

–Stamens (Androecium)

–Petals (Corolla)

–Sepals (Calyx)

•Each of these sets of parts may form a whorl or a series of spirals, with sepals outermost, pistils innermost

 

Compete, incomplete, perfect, imperfect

•complete - flowers having sepals, petals, stamens and pistils

•incomplete - flowers lacking one or more of these four parts

•perfect - flowers having both stamens and pistils, sepals and petals may or may not be present

•imperfect - unisexual flowers that have either stamens or pistils but not both

•monoecious - bisexual, the stamens and pistils in separate flowers but borne on the same individual

•dioecious - unisexual, the staminate and pistillate flowers on different individuals

•synoecious – plant with all flowers perfect

•polygamous – plant with mixture of perfect and imperfect flowers

Compete, incomplete, perfect, imperfect

Staminate and pistillate flowers in corn

Pistillate and staminate flowers in alder

Some terms

•connate – two or more parts of the same embryonic origin (i.e. the same type) that are united

•distinct – parts of the same origin that are not united or connate

•adnate – parts of different origin that are fused together (e.g. a stamen fused to a petal)

•free – unlike parts not joined together

 

Perianth = Calyx (all sepals) + Corolla (all petals)

Sympetalous

Flower symmetry

Flower symmetry

Flower symmetry

Flower symmetry

Flower symmetry

Flower symmetry

Spur

Androecium

Pistil and Carpel

•The carpel is the basic unit of a pistil

•A pistil may be composed of one to many carpels

•A simple pistil contains one carpel

•A compound pistil is composed of two or more carpels that are connate to some degree

 

Pistil

 

Development of Carpel from Sporophyll

Ferns (and other non-seed plants) produce spores on back of leaves called “sporophylls” (spore-producing leaves)

 

 

Fern leaves with spores (sporophylls)

Carpel development

•Consider that a sporophyll may (over many generations) roll under, with edges fusing

•Consider also that some of the earliest seed plants were “seed ferns” (which no longer exist)

Carpel fusion

Carpel connation

Placentation

Placentation Types

Carpel number

•To determine the number of carpels comprising an ovary, count these structures, and use the largest of those numbers:

–Stigmas

–Styles or style branches

–Lobes of ovary

–Locules

–Placentae

 

Pistil and Carpel

Ovary position and insertion of parts

Ovary position and insertion of parts

•hypanthium – bases of the three outer whorls (sepals, petals, stamens) are adnate (fused) into a single tube-like structure

 

Ovary position and insertion of parts

Nectaries

Inflorescence parts

Inflorescence Determination

Inflorescence Types

 

Head (Family Asteraceae)