In banyan tree, prop roots develop from the lower nodes of stem of banyan tree. They grow downwards and touch the soil. Prop roots are meant for support.
In sugarcane, stilt roots arise from the lower nodes of stem and enter the soil to provide strength to the plant. These protect the plant against winds.
Usually the terrestrial roots show a branched network that helps in anchorage and absorption of water and minerals from soil to the plant. While in aquatic plants, roots show modifications and deviation from their normal function. e.g., in plants like Trapa, Tinospora the roots are green and highly branched to increase the photosynthetic area, whereas in plants like Jussiaea. They get inflated due to air project out of water so to help the plant in floating and exchange of gases.
Difference between roots of aquatic plants and terrestrial plants are as
| Aquatic Plants | Terrestrial Plants |
|---|---|
| Roots may be absent, e.g., Wolffia. If roots are present they are not well developed. Usually thin adventitious roots are present. Vascular strands are poorly developed. Modified to carry out photosynthesis food storage and exchange of gases. |
Roots are well developed with root cap and root hairs and branches. Vascular bundles are well developed. Provide anchorage and help in absorption of nutrients from soil. |
Venation is the pattern of distribution of veins and veinlets in the lamina of leaf. It's pattern is different in monocot and dicot leaf.
| Monocot leaf | Dicot leaf |
|---|---|
The veins run parallel to each other within a lamina. It is called parallel venation. Parallel venation, e.g., grasses, wheat, maize, etc., (usually found in monocots). |
Veins and veinlets form a network in the lamina. It is called reticulate venation. Reticulate venation, e.g., Hibiscus, bean, pear etc., (usually found in dicots). |
The four floral parts of typical angiospermic flower are
Calyx It is the outermost whorl of the flower and members are called calyx or sepals. These are usually green and are protective in function (in bud stage).
Corolla It is composed of petals, usually bright coloured to attract insects for pollination.
Androecium It is composed of stamens, the male reproductive organ. Each stamen has stalk or filament and anther (containing pollen sac and pollen grains).
Gynoecium It is the female reproductive part and made up of one or more carpels. Each carpel has stigma, style and ovary.
Given below are a few floral formulae of some well known plants. Draw floral diagrams from these formulae.
(i) $\oplus \quad \mathrm{K}_{(5)} \mathrm{C}_{(5)} \quad \mathrm{A}_5 \mathrm{G}_\underline{(2)}$
(ii) $\mathrm{K}_{(5)} \mathrm{C}_{1+2+2} \mathrm{~A}_{(9)+1} \mathrm{G}_\underline{1}$
(iii) $\oplus \mathrm{K}_5 \mathrm{C}_5 \quad \mathrm{~A}_{5+5} \mathrm{G}_{(5)}$
(i) Floral Formula $\oplus \quad \mathrm{K}_{(5)} \mathrm{C}_{(5)} \quad \mathrm{A}_5 \quad \mathrm{G}_\underline{(2)}$ represents flowers of Solanaceae family.
(ii) Floral Formula $\% \quad K_{(5)} C_{1+2+2} \quad A_{(9)+1} \quad G_\underline{1}$ represents flowers of Fabaceae family.
(iii) Floral Formula $\oplus \underset{+}{\bigodot} \mathrm{K}_5 \mathrm{C}_5 \quad \mathrm{~A}_{5+5} \quad \mathrm{G}_{\underline{(5)}}$ represents flowers of Malvaceae family.
