Helioselenotropy

Bob-n’-Bobby, flawlessly flowless
as for cash flow, out to lunch, going
with the ebb and flow . . .
Bob: The seed of heliotropy is in it.
Bobby: A sunflower seed.
. . . of bee and wolf
for 1517 natural days,
but not at all out of (c)it(y):
Bob: A — wolf’s hooowl! — as a lullaby?
Bobby: The fruit of — who’s whooo! — of selenotropy.