Question:
Couldn’t find any ruling on the matter, is there any reason to assume it is not haadama?
Answer:
The books זאת הברכה (Birenbaum) שערי הברכה (Shtitzberg) and תורת הברכה (Feldman) all say that if the humus is ground well (shehakol), but if still pieces (haadama).
Sources: