Question

The reason why the fruits of Xanthium are dispersed by animals is that they
A. Are edible
B. Have hooks
C. Are sticky
D. None of the above

Answer 1

Hint: The annual plant Xanthium strumarium belongs to the Asteraceae family. It is thought to have originated in North America and has spread far over the world. The flowers are borne in separate unisexual heads: staminate (male) heads are located above the pistillate (female) heads in the inflorescence, and the species is monoecious. Two pistillate flowers are encircled by a spiny involucre in the pistillate heads. These two flowers develop into two browns to black achenes that are entirely encased by the involucre, which turns into a bur, after they fruit.

Complete answer:
Option A: Because the bur is buoyant, it disperses quickly in the water, allowing plants to flourish along streams. The bur, on the other hand, is clearly adapted to dissemination via animals by becoming entangled in their hair, as seen by its hooked projections.
So, option A is incorrect.
Option B: Xanthium is a flowering plant genus. The seeds of these plants are coated in stiff and hooked spines that cling to the animals' fur. By zoochorous, seeds are transported over great distances and spread through animals.
So, option B is correct.
Option C: Xanthium produces hairy seeds with hooks that get trapped in animals' fur and hide and propagate to far-flung locations. They are also spread by the wind.
So, option C is incorrect.
Option D: The seeds of these plants have sharp, hooked spines that attach to the fur of the animals. Seeds are transported over long distances and distributed by animals
So, option D is incorrect.

Hence, Option B is the correct answer.

Note:
A plant's seeds are transported throughout the world, resulting in the formation of various plants in various locations. Water, wind, and animals distribute seeds. The winged seeds of drumsticks, light seeds of grasses, hairy seeds of oak, and hairy fruit of sunflowers are all blown away by the wind. Xanthium seeds are spiky and have hooks that stick to the bodies of animals, allowing them to disperse. Xanthium strumarium has a wide range of therapeutic characteristics, including cooling, laxative, fattening, anthelmintic, tonic, digestive, antipyretic, and anodyne. Anti-inflammatory, diaphoretic, diuretic, emollient, and sedative.