The Stem

The adventitious roots of sweet potato modified for storage of food, these irregularly swollen rootlets are described as tuberous.

The pattern of arrangement of leaves on stem is known as phyllotaxy. This arrangement of leaves can be alternate, single leaf arising at each node, e.g., gurhal, opposite, arising of leaves on different side of the axis with base at same level opposite decussate (Calotropis), opposite superposed (guava) and whorled heterophylly is presence of more than on type of leaves and is observed in hydrophytes, while phyllode and phylloclads are modified leaf and stem and can be observed in Acacia and Cocofoba, Opuntia and Euphorbia respectivly.