sea lavender vs subshrub

sea lavender and subshrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea lavender	Yes	No	No	No
subshrub	Yes	No	No	No

As nouns, subshrub is a hypernym of sea lavender; that is, subshrub is a word with a broader meaning than sea lavender:

sea lavender: any of various plants of the genus Limonium of temperate salt marshes having spikes of white or mauve flowers
subshrub: low-growing woody shrub or perennial with woody base

Other hypernyms of sea lavender include suffrutex.

sea lavender (noun)	subshrub (noun)
any of various plants of the genus Limonium of temperate salt marshes having spikes of white or mauve flowers	low-growing woody shrub or perennial with woody base