What is a bud consisting of a short, thick stem that emits roots from below?

A bud consisting of a short, thick stem that emits roots from below is classified as a bulb. Bulbs are specialized underground storage organs that typically contain a short stem surrounded by fleshy scales (storage leaves) and are adapted for survival during unfavorable conditions. They serve as a means for the plant to store energy and nutrients, allowing it to endure periods of dormancy, such as winter. When the growing conditions become favorable, the bulb can produce shoots above ground while the roots develop below, helping the plant to thrive once again.

In contrast, nodes refer to the points on a stem where leaves or branches originate and do not serve the same underground storage purpose. Shoots are the above-ground parts of a plant that develop from buds, which include leaves and stems but do not describe the specific underground growth structure in question. Tubers, while also storage organs like bulbs, arise from the ends of underground stems and have a different structure and function than bulbs, making them distinct as well.