Final answer:
The roots that grow from stem nodes are called adventitious roots, serving for support, absorption, and asexual reproduction. Common in propagation of houseplants through stem cuttings, they also support plants like orchids and banyan trees in their unique habitats.
Step-by-step explanation:
The roots that grow from the nodes of the stems on certain plants like golden pothos are called adventitious roots. These roots serve various functions such as support, absorption, and asexual reproduction. Coleus and money plant are commonly propagated through stem cuttings which include these nodes. When a portion of the stem is placed in water or moist soil, the nodes can produce adventitious roots. Similarly, plants like African violet can root from leaves placed undisturbed in water.
In addition to supporting cuttings, adventitious roots assist epiphytes like orchids in absorbing moisture, while in the banyan tree, they grow from the branches downwards to support the plant. The screwpine also develops aboveground adventitious roots from nodes to stabilize in sandy soils. These structures are a prime example of modified stems, which may include rhizomes, stolons, and others, helping in propagation, support, and storage of nutrients.
Whilst not all stems grow upward, many run horizontally and are capable of producing vertical growth, such as stolons or rhizomes; and when meristematic zones at the nodes are stimulated, they can give rise to new growth following damage or another stimulus.