PROTO-POLYNESIAN ETYMOLOGIES
*Polo
Solanum sp. (Probably a generic term for Solanum species (Solanaceae) and similar berry-bearing plants).
From PROTO CENTRAL PACIFIC *poro, Solanum sp. (Perhaps a generic term for Solanum species and similar berry-bearing plants)

Proto Nuclear Polynesian: *Poro
REFLEXES IN SOME POLYNESIAN LANGUAGES:
Tongan: Polo (Solanum nigrum [Solanaceae])
Niuean: Polo (Solanum sp.)
Samoan: Polo (S. nigrum, s. ornans; Capsicum frutescens & C. annuum [Solanaceae])
Rapanui: Poporo ("An umbelliferous plant")
Tahitian: Porohiti (Solanim viride cv. anthropopophagorum) & 'oporo ("Pimento" [Capsicum sp.])
Hawaiian: Pōpolo (Solanum nigrum & others [Solanaceae]; Phytolacca sandwicensis [Phytolaccaceae]),
Tuamotuan: Poroporo (Solanum sp. )
Rarotongan: Poro (Solanum americanum, S. capsicoides, S. viride cv. anthropopophagorum)
Maori: Poro, Poroporo, Pōporo (Solanum aviculare; S. laciniatum; S. nodiflorum, S. nigrum)

Solanum nigrum
Solanum nigrum
Solanum aviculare
Solanum aviculare
(Te Māra Reo)

COGNATE REFLEXES IN SOME OTHER AUSTRONESIAN LANGUAGES
Lau (Fijian): Boboro (Probably Solanum sp. , "Shrub with clusters of black berries ")
Wayan Fijian: Boro (Several Solanum & Capsicum spp., Solanaceae)

NOTE - THIS PROTO-PAGE IS STILL UNDER CONSTRUCTION!

The word poroporo was thought at one time to to have been derived from a Proto-Oceanic word, reconstructed as *mpodo, however further research by the authors of The Lexicon of Proto Oceanic has indicated that the Solanum species to which this word typically refers were not present before contact with European and other newcomers over the last few centuries in the areas where the modern terms are found on which the reconstruction was based. It's probable that the apparently cognate words were introduced along with the plants bearing their names at some later period. The word seems rather to have originated in the Fiji-Rotuma area (the modern forms are poro in Rotuman and boro in Fijian) during the development of the Proto Central Pacific branch of Austronesian, still a long time ago (perhaps as much as 3,000 years), but more recently than Proto Oceanic.

Within Polynesia, including Aotearoa, the reflexes of *polo have been used to name a variety of members of the nightshade family (Solanaceae) and a few other plants that have similar berries (like the endemic "pokeberry" Phytolacca sandwicensis, not a member of the Solanaceae, in Hawaii). These names have been conferred on introduced as well as native plants. Thus throughout its range in Polynesia, Solanum nigrum, "black nightshade", and the similar S. nodiflorum and S. americanum, whether native or introduced, are likely to be known polo, poroporo, pöpolo, or some cognate term. One interesting plant is the cultivated variety S. viride cv. anthropophagorum -- the "cannibals' solanum" according to its Latin name, a Polynesian introduction into the Cook Islands, known there as poro'iti (the Tahitian porohiti).

The photograph below (left) is of a plant of one of the Hawai'ian pōpolo, Solanum americanum, in the Limahuli National Botanical Garden, Hanalei, Hawaii.

Popolo
Poporo
Phytolacca sandwicensis - "Hawaiian Pokeberry"
Further information : There is an excellent account of some of the Cook Islands species of pōpolo / Solanum (native and introduced) in the Bishop Museum database: http://cookislands.bishopmuseum.org/species.asp?id=6655.
Photographs: Phytolacca sandwicensis, David Eickhoff from Pearl City, Hawaii, USA -Licensed under Creative Commons Attribution 2.0 via Wikimedia Commons; other photos, R.B.

Te Mära Reo, c/o Benton Family Trust, "Tumanako", RD 1, Taupiri, Waikato 3791, Aotearoa / New Zealand. This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 New Zealand License