Among the rarest plants in the Hawaiian Islands is Cyanea truncata — Haha — which can be found in the Koʻolau Mountains of Oʻahu.

07-Cyanea truncata Plant-Sideways

Cyanea truncata grows 3-4 feet high and is found in dense native forests.  The plant produces large broad leaves up to 18 inches long.  Cyanea truncata was first discovered on Oʻahu in 1911 by famous botanist Joseph F. Rock who wrote the monograph on the Hawaiian Lobeliad Group in 1919.  The Hawaiian Lobeliad Group includes 6 genera and 126 different species most of which are geographically localized to a single island or to adjacent islands.   Cyanea truncata was later found on Molokai — it is endemic to Oʻahu and Molokai — but has since gone extinct on Molokai.  The plant is presently found only on Oʻahu.

01-Cyanea truncata under leaves-Med

Cute light pink-purple flowers grow upright from a leafy peduncle tucked within the base of the leaves. The flowers are about 1-1/2 inches in length and curve forwards.

02-Cyanea truncata flowers under leaves Cool-Cropped-Med

Known as the Punaluu Cyanea, the specific Hawaiian name for Cyanea truncata has been lost.  Haha is the generic name for Cyanea in Hawaiian.  The Hawaiians who knew the specific name of the plant died before the name could be passed on the Western botanists.

03-Cyanea truncata flower close-up-Med

When the flowers first open pollen is released by “white brushes” — male part of the flower — at the tip of the flower.  Only later does the stigma — female part of the flower — emerge which must be pollinated for seeds to develop.  The flowers were pollinated by native birds and insects and the decline in their numbers has hampered the plant’s comeback.  Botanists have been visiting the plants regularly to pollinate flowers by hand and collect seeds.

05-Cyanea truncata flowers under leaves Cool2-Med

According to sources in the rare native plant community, there is only one Cyanea truncata plant remaining in the wild.  It is extremely rare and endangered.  Fortunately the plant is under the capable hands of the Plant Extinction Prevention Program (PEPP) which has collected seeds, germinated them in the greenhouse and outplanted them in the field.  According to the last US Fish and Wildlife 5 year review in 2012 three populations have been outplanted.   I hope PEPP succeeds in bringing this exceedingly rare plant back from the brink of extinction.


A Monographic Study of the Hawaiian Species of Tribe Lobelioideae Family Campunulaneae, By Joseph Francis Rock, Bishop Musuem Press 1919

Cyanea truncata, The IUCN Red List of Threatened Species

Cyanea truncata – Punaluu cyanea, Wikipedia

Hawaiian Lobelioids, Wikipedia

5-Year Review Cyanea truncata (Haha), USFWS

Plant Extinction Prevention Program’s (PEPP) of Hawaii

Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae) by Thomas J. Givnish, Kendra C. Millam, Austin R. Mast, Thomas B. Paterson, Terra J. Theim, Andrew L. Hipp, Jillian M. Henss, James F. Smith, Kenneth R. Wood and Kenneth J. Sytsma, The Royal Society, 2008