Which of the following is not considered an aboveground, modified stem?

Which of the following is not considered an aboveground, modified stem?

• A. Crown
• B. Spur
• C. Pneumatophore
• D. Stolon

Answer: (C)

In plants, an aboveground modified stem is a stem that has been altered from a typical stem to perform an extra function, such as spreading or reproduction. Pneumatophore is a root modification that grows above the soil or water surface to help with gas exchange in flooded conditions; it originates from root tissue, not stem tissue, so it does not count as an aboveground, modified stem. The other two options illustrate aboveground stem modifications: a stolon is a horizontal stem that runs along the surface and can give rise to new plants at nodes, while a spur is a short, thickened shoot that bears flowers or fruit.

In plants, an aboveground modified stem is a stem that has been altered from a typical stem to perform an extra function, such as spreading or reproduction. Pneumatophore is a root modification that grows above the soil or water surface to help with gas exchange in flooded conditions; it originates from root tissue, not stem tissue, so it does not count as an aboveground, modified stem. The other two options illustrate aboveground stem modifications: a stolon is a horizontal stem that runs along the surface and can give rise to new plants at nodes, while a spur is a short, thickened shoot that bears flowers or fruit.