Neither. It is a form of grain.
Lotus is an aquatic herb
It is a herb.
herb shrub
Jute plant is a herb
herb
shrub
Wheat (the plant) is, as Cycling-rod says, a cereal grain, which is a type of grass grown for its "fruit". It's definitely not a shrub (a small to medium sized woody plant). It's also not an herb in the culinary sense (a plant grown for its aromatic or savory leaves or flowers), though it is a "herbaceous plant" in the botanical sense (a plant with no persistent woody stem above ground).
Shrub
Delonix regia
Corn is actually a grass and is a monocotyledonous plant. The corn kernals are the seeds of the plant.
Lemon is neither an herb nor a shrub. It is a tree.
herb