Barrel cactus have fibrous roots
Yes, the barrel cactus has roots.
One example is a cactus. Compact roots are close to the surface of the ground and obsorb water quickly.
Yes, a saguaro cactus has roots.
When it rains or there is a flood it spreads out its roots and absorbs as much water as possible without bursting.
The barrel cactus [Echinocactus and Ferocactusspp] has spreading, shallow, fibrous roots. It's the only kind of roots that a cactus plant has. The roots need to spread out in search of rare soil moisture. They also need to be shallow to catch the drops of dew, fog, or rain that drip to the ground and into the soil. They need to be fibrous, too, to take in water and dissolved nutrients, to send up the stem for the photosynthetic interaction with sunlight.
A Cactus has roots to absorb as much water as possible when it rain also to support the Cactus when it bad weather such as wind.
The size of the barrel cactus [Echinocactus and Ferocactus spp] depends upon the particular kind of cactus. For example, there are about 35 species within the genus Ferocactus. The species ranges from small, such as the 10 inch/25 centimeter crow's claw cactus [Ferocactus latispinus] to the tall, such as the 10 feet/3 meters candy barrel cactus [Ferocactus wislizeni].
To collect the rare amounts of water in the desert as quickly as possible before the water evaporates.
All cactus plants have fibrous, shallow roots. They need this kind of root in order to spread quickly and widely throughout the soil in search of moisture. They don't need thicker roots, because they don't have storage responsibilities within the cactus plant's division of labor. Instead, those responsibilities are carried out by the fleshy, thick stem.
No
Cacti get water from rainwater that is stored in the special roots of the cacti
Because the roots of the saguaro cactus are just below the surface.