Underground storage stems which grow horizontally in the soil are_______

Step 1: Analyze the question We need an underground storage stem that grows horizontally in the soil.

Step 2: Explain the concepts These are the main modified underground stems:

• Bulb: a very short, flattened stem with fleshy leaves that store food (e.g., onion). It is not horizontal. The stem is reduced to a disc.
• Runner (stolon): a stem that creeps above the ground surface and forms roots at its nodes (e.g., strawberry, Bermuda grass). It is not underground storage.
• Rhizome: a thick, fleshy stem that grows horizontally underground, stores food, and has nodes, internodes, and scale leaves (e.g., ginger, turmeric, spear grass, banana).
• Corm: a short, thick, upright underground stem that stores food (e.g., cocoyam, gladiolus). It grows vertically and is swollen, not horizontal.

Step 3: Match to the question

• Bulbs are a reduced disc-like stem with fleshy leaves, so A is wrong.
• Runners grow on the soil surface, so B is wrong.
• Rhizomes are horizontal, underground, and store food, so C fits.
• Corms are vertical and rounded, so D is wrong.

Answer: C. rhizomes

Tip: Link each term to a Nigerian example:

• Rhizome = ginger (horizontal)
• Corm = cocoyam (vertical, rounded)
• Bulb = onion (layers of fleshy leaves)
• Runner = creeping grass (above ground)

Remember: "Rhizome Reclines", because it lies flat underground.