Taproot

The largest and most dominant root from which other roots grow, mostly horizontally. It is often a storage organ. Taproots occur, among other plants, in beets and carrots.

Website

https://www.google.co.il/?gfe_rd=cr&ei=zqpQVMmwNLCAiAbEvYDADQ&gws_rd=ssl#q=taproot+botany+image