The root is usually the first organ which emerges from the seed. However, because roots spend most of their time below ground, they are understudied and under-appreciated. Root systems can be as extensive or more extensive than shoot systems.
Roots are generally nonphotosynthetic.
However, a few, like a small orchid I spotted in Puerto Rico, are capable of photosynthesis and in this particular case, the root is the major source of photosynthate. The roots are decidedly green and they have velamen . It may act like the large scales of Tillandsia , which are opaque when dry and translucent when wet. Scallion A Tap root has a dominant primary root and lateral roots which are produced in a regular sequence. Fibrous root systems do not have a dominant Primary root.