The New Zealand Railways Magazine, Volume 10, Issue 11 (February 1, 1936)
An old colonist, relating recently her early-days’ experiences on the West Coast of the South Island, said that she found, in lieu of other vegetables, “native fern made a useful item for the pot.” They called it “pick-a-pick.” She didn't know how it came to be given that name, but there it was. Possibly she thought the name came from the act of picking it. It is curiously interesting to trace the derivation of such terms used by the old-timers, and some of which are still heard from those who have picked them up in the bush or on the farms. They are mostly corruptions of the original Maori words. “Pick-a-pick” is really pikopiko, descriptive of the curled fronds of various small ferns, called generally mauku.
This pikopiko boiled with pork or other meat—once upon a time it was a favourite trimming for “long-pig”—is a tasty bit.
The derivation of “pick-a-pick” resembles that of “biddy-bid”—or “bid-a-bid” as I have heard it—the stickfast burr that gives wool-growers such trouble. Correctly this is piripiri; it is also known as hutiwai. The ignorant or careless pioneers quickly transmuted the Maori word; they had a way of making r's into d's, as in puriri, which easily became “boo-diddy”