T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Pittosporum ralphii (Ralph's Kohuhu)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order: Apiales
Family: Pittosporaceae
Genus: Pittosporum
Species: P. ralphii
Binomial name: Pittosporum ralphii
Common name: Ralph's Kohuhu, Karo.

Pittosporum ralphii is a hardy North Island evergreen shrub that will handle coastal conditions. It grows to 6m in height and a spread up to 5 m. Naturally occurring only in the north island. It grows between latitudes 37° 30' south and 40°south in the Central North Island, East Cape, along the Wanganui and the Patea rivers in Taranaki, Hawkes Bay, Rangitikei. Manawatu, Manawatu Gorge and Pahiatua. Its habitat is lowland to lower montane forest margins and stream sides. It is abundant on cliffs and gorges from 0 to 900m altitude. It is now widely cultivated throughout New Zealand.
The leaves of P. ralphii are thick & leathery ( 12.5cm long and 5cm wide) with their lower surfaces densely clad with white tomentum. The leaves usually have an undulating margin. It is similar to P. crassifolium but has a rounded habit and larger, darker-green leaves. 
The flowers which appear in spring are hermaphrodites (have both male and female organs) and are 1cm wide with petals which are a dark red. Following flowering the seed capsules ripen in summer and when opened display an orange-yellow inner surface and black seeds.

Photographed at Otari Native Botanic Garden and Wilton's Bush Reserve. Wellington.

The under surface of a leave showing the whitish  tomentum.