thorniness vs tartness

thorniness and tartness both are nouns.

Word	Noun	Adjective	Verb	Adverb
thorniness	Yes	No	No	No
tartness	Yes	No	No	No

As nouns, thorniness and tartness are synonyms defined as:

Other synonyms of thorniness include acerbity, acrimony, bitterness, jaundice.

thorniness (noun)	tartness (noun)
the quality of being covered with prickly thorns or spines	a sharp sour taste
a rough and bitter manner	a rough and bitter manner
The property of being full of difficulties, complexities, or controversial points.	the taste experience when vinegar or lemon juice is taken into the mouth