Jessa
Abad
Angeline
Icaro
Agnes Escario
Carlito Saulon Jr.
Dorina Araojo
Joyce Cardano
Joyce Cardano
ProfEd. 7b (M.W. 7:00-8:30 A.M.)
F l o w e r
Flower
is a component of the shoot system and is the characteristic feature of
angiosperms. Flower is responsible for the development of seed. It is the
plant's reproductive structure. Sexual reproduction in plants is enabled by
flowers and it is the sign of plants survival.
Flower
is also known as bloom or blossom. The main biological function of flower
is reproduction; the flowers provide a mechanism for the union of sperm
with eggs. Flowers produce seeds and fruits. Many flowers are attractive to
animals and attract vectors for the transfer of pollen grain.
Flower is a highly specialized shoot and is
modified and ceased to grow to house the reproductive structures. They are
usually bright colored to attract insects for pollination. Flowers
that are not colorful are pollinated by wind. All flowers have
the basic plan having four main parts: sepals, petals, stamens and
carpels. They are usually both male and female. The stamen is
the male part of the plant and carpel is the female part of the plant.
Flower Definition
Flowers are the reproductive organs of plants. Flower is the modified
vegetative shoot and is meant for sexual reproduction. Flower arises
from a modified leaf called bract. It consists of a very short axis on
which whorls of different parts of the flower are present.
Peduncle
A stalk supporting an inflorescence, which is the part of the
shoot of seed plants where flowers are formed in the flower.
Receptacle
Receptacle
is the stem portion, it is found at the base in the center of the flower. The
internodes are short and the number of leaves is small. Hence, receptacle
is not usually a large part of the flower.
Sepals
Sepals
form the outermost whorl of the floral structure. They are mostly but not
always green and are leaf-like in appearance. Sepals are similar to the foliage
leaves of the plant. Sepals are collectively known as the Calyx.
The major function of the calyx is the protection of flower parts during early
development of the flower or the bud.
Petals
Petals
are present above the sepals whorl. Petals are larger than the sepals, they are
brightly colored, leaf-like, broad and are thin organs. The petals collectively
are known as the Corolla. Corolla is the attractive part of the
flower. They provide additional protection and attract insects to facilitate
pollination of the flower.
The
leaf-like organs, the sepals and the petals are together known as the perianth
of the flower. They are similar in appearance.
Carpels
Carpels
are one or more in number and are located in the upper center of the flower.
Collectively the carpels are known as gynoecium. Carpels are made of three parts:
Ovary. Style and Stigma.
1.
Ovary is the structure present
at the base of the carpel. It is an enlarged narrow region bearing one or more
ovules.
2.
Style is the slender,
neck-like portion of the carpel the leads to the ovary.
3. Stigma is of variety of
shapes and sizes. It present at the tip of the carpel and is sticky to collect
pollen grains.
Stamens
Stamens are
located inside the corolla and are leaf-like appearance. Stamens are the male
part of the flower and produces pollen. Stamens consists of a filament and an
anther. Stamens are collectively called androecium.
Anther is the sac located
at the tip of the filament that contains pollen.
Filament is the stalk that
connects to and holds up the anther.
Nectaries are often associated
with flowers and are found at the receptacle, nectaries produce sugary nectar
which attracts insects.
Bract
Flower
consists of a stalk and is called pedicel. The flower is described as sessile if the pedicel is absent. Flowers are
known as ebracteate in
the absence of bracts. Bract-like green structures are present on the pedicel
and are called bracteoles and
the flower with presence of bractiole is called bracteolate and absence of bracteoles is described
as ebracteolate.
Bracts
are of various types:
1.
Foliaceous: Leaf-like bracts
as in Adhantoda.
2.
Petaloid: Petal like bracts,
peatloids is bracts where they are large and colored as in Bougainvillea.
3.
Involucre of bracts: Here many
bracts form one or more whorled structures called involucres. Example:
Head inflorescence of Helianthus.
Calyx
Sepals
are collectively known as calyx. It forms the outermost whorl of a flower. They
are usually green in color and their typical function is protection for the
flower in bud stage and also supports the petals when in bloom. Morphologically
sepals are modified leaves.
Corolla
Corolla
makes up the second whorl of the flower and it is composed of petals. They are
brightly colored, making the corolla conspicuous, and attractive. Petals are
also scented in many cases. They help attracting insects for pollination.
Pistil
Pistil
is the female reproductive part of a flower. It is located centrally and
consists of a swollen base, which is the ovary. The ovary contains the ovules
which are the potential seeds; a stalk or style and a stigma which the pollen
receptive tip. Pistil in collective sense forms the gynoecium.
Pistil is the word
used to describe each unit of the gynoecium. A pistil consist of a single
carpel which can be a monocarpous or apocarpus gynoecium, in which case it is
called a simple pistil. It also may be of fused carpels or a syncarpous
gynoecium and is called a compound pistil.