genja -gej- gismu

x1 is a root [body-part] of plant/species x2; [metaphor: immobile, supporting, nourishing].

See also jamfu, jicmu, patlu, samcu, spati, krasi.

In notes:

jamfu
x1 is a/the foot [body-part] of x2; [metaphor: lowest portion] (adjective:) x1 is pedal.
jicmu
x1 is a basis/foundation/underlying or fundamental principle of x2; x1 is at the bottom of x2.
krasi
x1 (site/event) is a source/start/beginning/origin of x2 (object/event/process).
patlu
x1 is a potato [an edible tuber] of variety/cultivar x2.
samcu
x1 is a quantity of cassava/taro/manioc/tapioca/yam [edible starchy root] of species/strain x2.
spati
x1 is a plant/herb/greenery of species/strain/cultivar x2.
gejystani
x1 is a rhizome/rootstalk of plant/species x2.
tu'uspa
x1 is a vascular plant
gulrota
x1 is a carrot of species / variety / cultivar x2
morkova
x1 is a carrot of species / variety / cultivar x2
porkana
x1 is a carrot of species / variety / cultivar x2
uortele
x1 is a carrot of species / variety / cultivar x2