Morphology of Flowering Plants

Types of roots.

Types of roots.

Three types of roots are

1. Primary roots - It is the direct elongation of the radicle.

2. Lateral roots - It arises from the primary root .

3. Adventitious root - It arises from any part of the plant other than the radicle.

Root systems

Tap root system - found in dicots such as mustard

Fibrous root system - found in monocots such as wheat and rice

Regions in the root. mention cell organisation and function

Zone of maturation - cells are fully differentiated and matured. Hair grows from this zone.

Zone of elongation - cells undergo rapid elongation and enlargement. Helps in growth of the root

Zone of meristematic activity - cells are small, thin walled, dense cytoplasm and undergo division repeatedly.

Root cap - thimble like structure protects the root apex while passing through the soil

Describe root hairs and their function.

Root hairs are delicate thread like epidermal cells. they absorb water and minerals from the soil

Parts and functions of the stem

Parts

1. nodes

2. internodes

3. buds - terminal and axillary

axillary - flowers and branches

Functions

1. bears leaves, flowers, branches and buds

2. helps in food storage, support, protection and vegetative propagation

Leaf

develops at node, bears axillary bud - flowers and branches.

develops from shoot apical meristem

arranged in acropetal order

Parts of leaf and functions of veins?

Parts

1. leaf base

2. petiole

3. lamina

4. midrib

Functions

1. transports mineral, food and water to different parts of leaf

2. provides rigidity to the leaf blade

Modifications in leaves with examples

Expanded sheath - the leaf base expands into a sheath covering the stem partially or wholly. Eg - monocots.

Pulvinus - the swollen leaf base. Eg - some leguminous plants

Types of compound leaf with example example.

Pinnately - leaflets are present to a compound node called rachis. Eg - neem

Palmately - leaflets are attached at a common point, at the top of the petiole. Eg - silk cotton

Different phyllotaxy

Alternate - China rose, mustard

Opposite - guava, calotropis

Whorled - astonia

Different types of inflorescence?

Racemose

• The main axis continues to grow.

• The flowers are borne laterally in an acropetal order.

Cymose

• The main axis terminates in flower.

• Growth is limited.

• Flowers are borne in a basipetal order.

Flower based on symmetry

Actinomorphic - radial symmetry. Eg - mustard, chilli, datura

Zygomorphic - bilateral symmety. Eg - pea and bean flowers

Asymmetry - irregular symmetry. Eg - canna

Bract?

Reduced leaf found at the base of the pedicel

Flowers based on arrangement of flowers appendages

Hypogynous - superior ovary. Eg - mustard, brinjal, china rose

Perigynous - half inferior ovary. Eg - plum, rose and peach

Epigynous - inferior ovary. Eg - guava, cucumber and ray florts

Aestivation

Valvate - calotropis

Twisted - China rose, lady finer and cotton

Imbricate - cassia and gulmohar

Vexillary - pea and bean flowers

Types of stamen

Monoadelphous - United stamen in one bunch. Eg - China rose

Diadelphous - stamen United in two bundles. Eg - pea

Polyadlephous - stame United in more than two bundles. Eg - citrus

Placentation with example

Marginal - pea

Axile - china rose, lemon, tomato

Parietal - mustard and argemone

Free Central - dianthus and primrose

Basal - sunflower and marigold