Pōpolo

Pōpolo or nightshade is a rare plant only found on Oahu and Kauai. As the book mentions, it is extinct on Oahu, but outplanting has brought it back. When flowering and fruiting it is somewhat easy to identify as the white flowers are upside down.

Background Information

A nickname for this plant is the Hawaiian Horsenettle. It is an endemic species and is on the federally endangered list. The flowers are white and bloom sporadically throughout the year, although I was able to see it in bloom early May.

Pōpolo

I took this picture almost in full bloom. The fruits were coming out already. This was taken in the Waianae Mountain Range. It grows well in the gulches.

Source