Concept:Wind-pollinated flowers are adapted for airborne pollen transfer, not for attracting animal pollinators.
Explanation:In wind-pollinated flowers, nectar is usually absent because insects are not needed to attract them.
The flowers are generally not scented and often lack bright colours or showy petals.
Their stigmas are typically large and feathery so they can easily trap pollen grains carried by wind currents.
The pollen grains are smooth, light, and produced in large quantities to remain airborne and travel long distances.
Rough, spiny pollen surfaces are a common feature of insect-pollinated flowers because the spines help pollen grains stick to the bodies of visiting insects.
Therefore, the statement about rough spiny surfaces does not describe a wind-pollinated flower.
Answer:C. The pollen grains have rough spiny surfaces.