Morphology of Flowering Plants - Morphology of Root, Stem and Leaf

The root system is divided into three types: Tap root (originates from the radicle, e.g., $Mustard$), Fibrous root (originates from the base of the stem, e.g., $Wheat$), and Adventitious root (originates from parts other than the radicle, e.g., $Banyan$ tree).

The root regions consist of the root cap, the zone of meristematic activity (high $mitosis$ rate), the zone of elongation, and the zone of maturation (where $root\ hairs$ are present for absorption).

Modification of roots: Prop roots ($Banyan$), Stilt roots ($Maize$, $Sugarcane$), and Pneumatophores for respiration in halophytes like $Rhizophora$ (to obtain $O_2$).

Stems develop from the plumule and bear nodes and internodes. Modifications include underground storage (Rhizome in $Ginger$, Tuber in $Potato$, Corm in $Colocasia$), stem tendrils for climbing ($Cucumber$), and thorns for protection ($Citrus$).

Phylloclades are flattened or cylindrical green stems that perform photosynthesis ($CO_2$ fixation) in xerophytic plants like $Opuntia$ and $Euphorbia$.

Venation refers to the arrangement of veins: Reticulate (network-like, usually in $Dicots$) and Parallel (veins run parallel, usually in $Monocots$).

Phyllotaxy is the pattern of leaf arrangement: Alternate (one leaf per node, e.g., $China\ rose$), Opposite (two leaves per node, e.g., $Calotropis$), and Whorled (more than two leaves per node, e.g., $Alstonia$).