PARTS OF PLANTS

ROOTS

Roots serve a variety of functions, among them storage, collection of water and nutrients, and support

Cultivated Carrot

The carrots we eat are actually the plant’s enlarged main root, called the taproot. An important storage organ, the root provides food for the 1 to 1.5 m of stem growth that occurs if the plant is left in the ground for a second season.

Epiphyte

Although similar in structure and function to the roots of plants living in soil, the roots of epiphytes, or air plants, are adapted for growth above the soil surface. The plants, usually growing on the branches or trunks of trees and shrubs, where there is increased access to light, develop aerial roots.

Fiborous Root

The main roots of many plants divide as they grow downwards. The branches, called lateral roots, further divide to form a network that anchors the plant in the ground. New growth takes place at the ends of the smallest roots. Tiny root hairs absorb water and nutrients from the soil, channeling them up to the stem and leaves of the plant through the xylem tissue at the centre of the root.

Stems

The stem of a plant provides pathways for the distribution of water and nutrients between the roots, leaves, and other parts of the plant. The bluebell’s herbaceous stem lacks lignin, the material that stiffens supportive woody stems. For this reason, herbaceous plants are generally limited in size, especially in their height. Spurges and cacti, their leaves reduced to needles to prevent evaporation of water in a dry climate, consist entirely of stem material. Potatoes and other tubers are swollen, food-storing underground stems that nourish growing buds. The stems of some plants are adapted for protection, as in the hawthorn. Others actively compete for sunlight, using touch-sensitive, curling tendrils or other structures to climb upwards.

Varigated Leaves

The green colour in a normal holly leaf results from the uniform distribution of the green pigment chlorophyll. In a variegated leaf this important photosynthesizing pigment is reduced or lacking altogether in certain parts of the leaf, as indicated by the yellow colour. Though the holly plant’s spines defend it against leaf-eating animals, its variegated leaves will generally not survive in nature because of this pigment deficiency.

Source : Google , Manorama , Wikipedia.