The Half-flower’s Many Names

Gerald McCormak, CINHT,

Map depicting the names of the Half-flower different islands of the Cook Islands

One of the most widespread and conspicuous coastal shrubs in the Cook Islands has bright green, fleshy, hand-sized leaves; small white flowers, and grape-sized white fruit. The English name Half-flower (Scaevola taccada), although not widely used, refers to the fact that the petals are restricted to one half of the flower.

The search for the Mäori name, as usual, started on Rarotonga where the plant is Poºutukava. Further afield, it is Köpara on Aitutaki and Käkäkina on Mangaia. Thankfully the three islands of Ngäpütoru (ºÄtiu, Maºuke and Mitiºäro) were in agreement with Ngaºu.

Scaevola taccada, Flower and leaves – Cook Islands, Miti‘āro – Gerald McCormack

It was a pleasant surprise to find the Northern Group following Ngäpütoru, each replacing the glottal stop (º) with letters not used in Southern Mäori: Ngahu (Manihiki and Rakahanga), Ngasu (Penrhyn), Ngashu (Palmerston) and Ngayu (Pukapuka and Nassau) – the latter pronounced “nga-thu”.

Without losing the traditional names from each island, it is sometimes convenient to have a single national Mäori name to use, for example, on posters and in school textbooks. In this context it would be confusing to use the Rarotonga name Poºutukava, because the Outer Islands use this name for another common coastal shrub – a shrub with silvery leaves, yellow flowers and pea-like pods. And although this shrub, the Silverbush (Sophora tomentosa), is on the Matavera coast, it has no known Rarotonga name.

Scaevola paulayi , Fruit, flower and leaves – Cook Islands, Ātiu – Gerald McCormack

As a result, the most convenient national names of these two common coastal shrubs are: Ngaºu for the Half-flower and Poºutukava for the Silver Bush. The scientific names for the Half-flower include Scaevola taccada, Scaevola koenigii, Scaevola frutescens and Scaevola sericea – the last having the most authoritative support at present.

On Rarotonga the flowers are white, while on Mitiºäro they are yellow, and on some islands there are plants with white flowers and other plants with yellow. In 1990, the yellow flowered Half-flower from Maºuke was named as a new species, Scaevola paulayi.

When it is necessary to talk accurately about the different species of Half-flower or Ngaºu, we can simply elaborate the common names to: White Half-flower or Ngaºu Teatea; and, Yellow Half-flower or Ngaºu Rengarenga.

First published CINEWS (21 May 1994)