The correct option is (c).
Explanation
Seed dispersal is the process by which seeds are spread from the parent plant to new locations to ensure species survival and reduce competition. Plants have evolved specific morphological adaptations to utilize agents such as wind (anemochory), water (hydrochory), or animals (zoochory) for transport.
Statement-wise Analysis:
- Statement 1 is Incorrect: Xanthium seeds are not dispersed by wind. Wind-dispersed seeds typically possess specific adaptations such as wings (e.g., maple, drumstick) or tufts of hair (e.g., dandelion, Calotropis) to increase buoyancy. Xanthium fruits are relatively heavy and lack aerodynamic structures required for wind transport.
- Statement 2 is Correct: The surface of the Xanthium fruit is covered with stiff, hooked spines. These hooks are a specialized adaptation for epizoochory (external dispersal by animals). They allow the fruit to latch firmly onto the fur of animals or the clothing of humans.
- Statement 3 is Correct: Because the hooked seeds attach securely to mobile agents (animals), they are carried significant distances away from the parent plant before falling off or being removed. This mechanism ensures the spread of the species to new and distant habitats.
Key Takeaway:
Xanthium serves as a classic example of zoochory (dispersal by animals), characterized by the presence of hooked spines that facilitate attachment to animal bodies, distinguishing it from wind-dispersed species.