Roots originate at some distance from the stem/soil interface in simple upright species. Consequently, the root grows through the Cortex for some distance before entering the soil.

Roots originate from the Pericycle. This is parenchyma tissue that is part of the stele. It is located just inside the Endodermis and forms a cylinder several cells thick which surrounds the Phloem & Xylem.

Once the roots have emerged from the stem, its branching is Dichotomous.

Upright Stem with Adventitious roots emerging from its subterranean base.

Same as above but at higher magnification.

Roots with Dichotomous Branching