“O, mickle is the powerful grace that lies
In herbs, plants, stones, and their true qualities:
For nought so vile that on the earth doth live
But to the earth some special good doth give,…”

(I’ve used this re. the invasive plant, garlic mustard.)

Also the following:

“Why then, the mustard without the beef. …Go, get thee gone, I say.” — Shakespeare, Taming of the Shrew, Act IV, Scene III.

“(T)he mustard was naught: now I’ll stand to it,…” — As You Like It: I, ii.

See article at http://www.clwa.us/PDF/Crystal_Whitecaps_2007_sum.pdf