The stem is the cactus body part in which water is moved, processed and stored. It also is the body part where breathing pores called stomata allow for the gas exchange necessary for keeping proper temperatures and stopping water loss. It takes on various forms. For example, it may look like a thick column, such as in the case of the giant saguaro cactus [Carnegie gigantea]. Or it may look roundly compact, such as in the case of the birthday cake cactus [Mammillaria hahniana].
Cactus
Cactus plants use their stems for storage. So that's where starches are stored. In fact, stems are where a cactus plant stores everything. Other, non cactus plants may use their roots for storage. But cactus roots are much too fibrous and shallow.
A cactus has no leaves but does have a stem.
Yes there are photosynthetic stems. Green stems carry out photosynthesis. Example: cactus
light refraction of the presence of chlorophyll.
Cactus stems are very thick because they store water.
Cactus are able to conserve water due to their stems. They have stems that are able to store water for when it is needed.
Their stems are thick and sponge-like.
Cactus stems get bigger for two main reasons. One reason is normal growth. The other is an increase in the amounts of stored water, nutrient solutions, and energizing photosynthetic products. This last reason is why a cactus is ribbed. Its ribbing allows the cactus to decrease its size when it has lesser amounts in storage, and to increase with greater amounts.
The roots absorb water and that makes the stem grow
Cacti are able to store water in their fleshy stems.
Cacti do not have leaves. However, some species can be propagated by cuttings from the stems.