The "wiliwili" is summer (dry season) drought deciduous. The dry season usually begins in late April or in May, and trees in the wild typically lose all of their leaves before they bloom. Trees in cultivation may retain much of their foliage through blooming time. The flowers appear in the first half of the dry season, from April through July. They form on horizontal or nearly horizontal racemes that are long. The flower color may be orange, yellow, salmon, greenish or whitish. Sometimes all of these colors occur in a single population. The standard petal is erect, not enclosing the other petals. Like all of the erythrinas, the wiliwili is pollinated by birds. The horizontal raceme and the erect standard are adaptations to pollination by passerine birds. Many other erythrinas are pollinated by hummingbirds, which do not occur in Hawaii.