Describe various stem modifications associated with food storage, climbing and protection.
(i) Food storage – Underground stems of potato, ginger, turmeric, Samarkand, Colocasia are modified to store food in them.
(ii) Climbing – Stem tendrils which develop from axillary buds, are slender and spirally coiled and help plants to climb such as in gourds (cucumber, pumpkins, watermelon) and grapevines.
(iii) Protection – Axillary buds of stems may also get modified into woody, straight and pointed thorns. Thorns are found in many plants such as Citrus, Bougainvillea.