Holokea (Cyanea horrida)

loading
Cyanea horrida in flower
loading
Loading more images and videos...

Holokea fact file

Holokea description

KingdomPlantae
PhylumTracheophyta
ClassMagnoliopsida
OrderCampanulales
FamilyCampanulaceae
GenusCyanea (1)

As of 2003, less than 20 individuals of this incredibly rare plant were believed to remain (2). Holokea is a palm-like tree, with leaves composed of leaflets arranged each side of a central stalk. Each leaf measures 20 to 37 centimetres long, and 10 to 19 centimetres wide, and has a green upper surface that bears small, sharp projections. The underside is a paler shade of green, and is covered with hairs as well as small, sharp projections (2). The flowers of holokea are borne in clusters of five to eight, and whilst each flower is just one centimetre wide and eight centimetres long, their attractive colouring (blackish-purple or greenish-white tinged with purple), makes them clearly evident amongst the green leaves. At certain times of the year, holokea also bears yellow berries, each one measuring up to 2.5 centimetres long (2).

Also known as
prickly cyanea.
Size
Height: 1 – 4 m (2)
Top

Holokea biology

The prickles borne on the leaves of holokea are believed to have evolved as a defence against flightless geese and geese-like ducks that used to inhabit the Hawaiian Islands, but which became extinct well over 1,000 years ago (3).

Top

Holokea range

Top

Holokea habitat

Holokea inhabits rainforest and the edges of subalpine forest, at altitudes between 1,520 and 2,000 metres (2).

Top

Holokea status

Holokea is classified as Critically Endangered (CR) on the IUCN Red List (1).

IUCN Red List species status – Critically Endangered

Top

Holokea threats

This Critically Endangered species is thought to be threatened by the impact of feral pigs, weeds, as well as possibly rats and invertebrates (1) (4). Holokea's tiny population also makes it incredibly vulnerable to natural events such as disease, extreme weather, and fire, which could have a catastrophic impact on the species.

Top

Holokea conservation

There appear to be no specific conservation measures currently in place for this extremely rare species.

Top

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Top

Glossary

Endemic
A species or taxonomic group that is only found in one particular country or geographic area.
Invertebrates
Animals with no backbone.
Top

References

  1. IUCN Red List (January, 2008)
    http://www.iucnredlist.org
  2. Wagner, W.L., Herbst, D.R. and Sohmer, S.H. (1999) Manual of the Flowering Plants of Hawai’i. Bishop Museum Press, Honolulu.
  3. Givnish, T.J., Sytsma, K.J., Smith, J.F. and Hahn, W.J. (1994) Thorn-like prickles and heterophylly in Cyanea: adaptations to extinct avian browsers on Hawaii?. Proceedings of the National Academy of Sciences of the United States of America, 91(7): 2810 - 2814.
  4. NatureServe (August, 2008)
    http://www.natureserve.org
X
Close

Image credit

Cyanea horrida in flower  
Cyanea horrida in flower

© Hank Oppenheimer/ Plant Extinction Prevention Program

Hank Oppenheimer
hmo3500@earthlink.net

X
Close

Link to this photo

ARKive species - Holokea (Cyanea horrida) Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

This species is featured in:

Which species are on the road to recovery? Find out now »

Help us share the wonders of the natural world. Donate today!

Blog RSS