huckleberry oak vs shrub

huckleberry oak and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
huckleberry oak	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of huckleberry oak; that is, shrub is a word with a broader meaning than huckleberry oak:

huckleberry oak: a low spreading or prostrate shrub of southwestern United States with small acorns and leaves resembling those of the huckleberry
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of huckleberry oak include bush.

huckleberry oak (noun)	shrub (noun)
a low spreading or prostrate shrub of southwestern United States with small acorns and leaves resembling those of the huckleberry	a low woody perennial plant usually having several major stems