gather vs gather up

gather is a noun but gather up is not a noun.

Word	Noun	Adjective	Verb	Adverb
gather	Yes	No	Yes	No
gather up	No	No	Yes	No

gather (noun)	gather up (noun)
the act of gathering something
sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching

gather (verb)	gather up (verb)
increase in amount by collecting or gathering	take and lift upward
increase or develop	gather or collect
conclude from evidence
assemble or get together
draw together into folds or puckers
look for (food) in nature
draw and bring closer
collect in one place
get people together