flower vs burst forth

flower is a noun but burst forth is not a noun.

Word	Noun	Adjective	Verb	Adverb
flower	Yes	No	Yes	No
burst forth	No	No	Yes	No

As verbs, burst forth is a hyponym of flower; that is, burst forth is a word with a more specific, narrower meaning than flower:

Other hyponyms of flower include effloresce.

flower (noun)	burst forth (noun)
a plant cultivated for its blooms or blossoms
reproductive organ of angiosperm plants especially one having showy or colorful parts
the period of greatest prosperity or productivity

flower (verb)	burst forth (verb)
produce or yield flowers	be unleashed; emerge with violence or noise
	come into or as if into flower
	jump out from a hiding place and surprise (someone)