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


Lobelia physaloides (NZ hydrangea, Koru)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order: Asterales
Family: Campanulaceae
Genus: Colensoa
Species: C. physaloides
Scientific name: Lobelia physaloides
Synonym:  Colensoa physaloides, Pratia physaloides 
Common name: Koru, NZ hydrangea,

Lobelia physaloides succulent, herbaceous shrub (1.5m) which has a similar leaf shape and size (8-18 cm) to that of the unrelated Hydrangea macrophylla but L. physaloides leaves are more soft and tender.
It is endemic to the Three Kings, Poor Knights, Taranga and Rakitu Islands, mainland northern North Island from Te Paki to about Whangarei and Trounson Kauri Forest. Within this area its distribution is the coastal and lowland forests were it is localised to damp, shady spots, often in gullies. 

During August and January racemes of 10 to 15  long tubular, two lipped flowers appear on purple fuzzy stalk. Petal bases are deep blue fading to pale blue at the tips. Each flower is about 50mm long. By autumn the flowers are followed by purple, blue, white with blue streaks, or white, shiny berries (15mm long). These berries contain large amounts of yellow or brown seeds.
Disturbance and browsing by cattle, goats etc. and the loss of forest habitat has placed it on the nationally threatened plant list.
It is  highly palatable to slugs and snails.

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

New flowering buds.







The berries are just forming.






Top surface of a leaf

Underside of a leaf