(idiomatic) A small amount, as in the phrase huckleberry above a persimmon.
Example: A small round fruit of a dark blue or red color of several plants in the related genera Vaccinium and Gaylussacia.
1913, Joseph C. Lincoln, chapter 1, Mr. Pratt's Patients:
I stumbled along through the young pines and huckleberry bushes. Pretty soon I struck into a sort of path that, I cal'lated, might lead to the road I was hunting for. It twisted and turned, and, the first thing I knew, made a sudden bend around a bunch of bayberry scrub and opened out into a big clear space like a lawn.
A shrub growing this fruit.