adventitious
the radicle is also growing and producing the primary root. As it grows downward to form the tap root, lateral roots branch off to all sides, producing the typical dicot tap root system. In monocot seeds Figure 32.21 , the testa and tegmen of the seed coat are fused. As the seed germinates, the primary root emerges, protected by the root-tip covering: the coleorhiza. Next, the primary shoot emerges, protected by the coleoptile: the covering of the shoot tip. Upon exposure to light i. when the plumule has exited the soil and the protective coleoptile is no longer needed , elongation of the coleoptile ceases and the leaves expand and unfold. At the other end of the embryonic axis, the primary root soon dies, while other, adventitious roots roots that do not arise from the usual place i. the root emerge from the base of the stem. This gives the monocot a fibrous root system.