Morphology of Flowering Plants (copy)

plants which have a fibrous root system

Monocotyledonous plants

plants which have a tap root system i.e. primary, secondary, and tertiary, etc. roots

Dicotyledonous plants

the roots that arise from any part of the plant other than the radicle

Adventitious roots

protects the tender apex of the root

rootcap

just above the rootcap and extends to a few mm above; consists to rapidly dividing meristematic tissues

Meristematic region

region above the meristematic region; the meristematic cells stop diving and start elongating

Region of elongation

region above the region of elongation; cells stop growing and elongating, becomes a mature plant cell; root hair arises in this region from the epidermal cells

Region of maturation

roots that perform functions other than absorption of water and nutrients. It includes,

1) Storage roots: tap roots (carrot, turnip) and adventitious roots (sweet potato) become swollen with stored food.

2) Prop roots: massive pillar like outgrowths of aerial branches which grown downward to support the expanding tree (banyan)

3) Stilt roots: supporting roots which arise from the basal nodes just above the ground (maize, sugarcane).

4) Pneumatophores: branches of roots that grow vertically above the ground. They have openings called pneumathodes for the exchange of gases. Found in plants growing in marshy regions (rhizopora).

Modified roots

The ability of an organism to survive from one germinating season to the next, especially under unfavorable conditions such as drought or winter.

Perennation

modified to store food, organs of perennation and vegetative propagation; turmeric, ginger

Underground stems

slender, spirally coiled structures; help weak stemmed plants climb on to support; cucumber

Tendrils

each leaf possesses a bud in its axil which is known as the axillary bud.

Axillary bud

woody, straight, pointed structures; protect plants from browsing animals; develop from axillary buds; citrus, bougainvillea

Thorns

helps in vegetative propagation in strawberries and grasses

Sub-aerial stem

helps produce a new plant from the base of the main stem in jasmine and mint

Slender lateral branch

In chrysanthemum and pineapple, a lateral branch of stem which originates from the basal and underground part of the main stem grows horizontally beneath the soil and comes out obliquely upward and gives rise to a new plant.

Lateral branch of stem

stalk of the leaf

petiole

green expanded part of the leaf; main area of photosynthesis; supported by veins and veinlets

lamina

The middle prominent vein on a lamina

Midrib

provide rigidity and support; are the channels of transport of water, minerals, and food material

Veins

arrangement of veins and veinlets in the leaf

Venation

when the midrib and its branches make a network (reticulum) on the lamina; characteristic property of dicot plants

Reticulate venation

when the veins on the lamina run parallel to each other; characteristic property of monocot plants

Parallel venation

when its lamina is entire OR when incised, the incisions do not run down to the midrib; mango

Simple leaf

when its lamina is incised down to the midrib into a number of segments called leaflets, each with a very short stalk; a leaf HAS a bud in its axil, however, a leaflet DOES NOT have a bud in its axil

Compound leaf

leaflets are arranged along the length of the rachis (represents the midrib); neem, rose

Pinnately Compound leaf

leaflets arise from a common point i.e. the tip of the rachis/petiole; silk cotton

Palmately Compound leaf

mode of arrangement of leaves on the stem/branch; may be alternate, opposite, or whorled

Phyllotaxy

Tendrils (pea), Spines (opuntia), Phyllode (australian acacia), Pitcher (nepenthes), Food storage (onion+garlic), vegetative reproduction (bryophyllum)

Modifications of Leaves

the manner in which the flowers are arranged on the flowering axis

Inflorescence

stalk of the flower

Pedicel

the swollen end of the pedicel on which the floral leaves are arranged in whorls

Thalamus/Torus

flower with both androecium and gynoecium

Bisexual/Hermaphrodite flower

flower that has either only androecium (male) or only gynoecium (female)

Unisexual flower

the flower cannot be divided into two similar halves along any vertical plane passing through the centre; canna

Asymmetric (irregular) flower