| rootstock |
| root(noun, cause, base, source, core) |
| rootstalk |
| radix(cause, quick, source, root, origin) |
| bulb |
| tuber(noun, cause, quick, source, root) |
| beginnings(cause, quick, source, origin, stem) |
| center(cause, source, root, origin, mainspring) |
| core(cause, source, root, origin, mainspring) |
| corm |
| mainspring(cause, quick, source, root, origin) |
| marrow(cause, source, root, origin, mainspring) |
| nub(cause, source, origin, bulb, tuber) |
| quick(cause, source, root, origin, stem) |
| radicle(cause, quick, source, root, origin) |
| rhizomatous |
| rhizomes |
| rock bottom(expression, cause, quick, source, origin) |
| starting point(expression, cause, quick, root, origin) |
| stem(noun, cause, quick, source, origin) |