Hawaiian silversword (Argyroxiphium sandwicense)

Hawaiian silversword in full flower
Hawaiian silversword in full flower

Hawaiian silversword fact file

Hawaiian silversword description

KingdomPlantae
PhylumTracheophyta
ClassMagnoliopsida
OrderAsterales
FamilyCompositae
GenusArgyroxiphium (1)

The striking Hawaiian silversword stands out starkly against the volcanic landscape of its habitat. This plant consists of a rosette of narrow, pointed silver leaves that may be up to 40 centimetres long (2), together forming a silvery sphere (3). The common name for this species comes from the shape of the leaves; these are stiff, narrowly sword-shaped, and covered with silky, silver hair (2). These plants are particularly dramatic when in flower; the tall inflorescence grows up from the rosette of leaves and may reach three metres tall, and 75 centimetres wide (2). Between 50 and 600 compound flower heads are carried on the inflorescence; the individual flowers are pink or wine red in colour (2). Two subspecies are recognised; Argyroxiphium sandwicense subsp. macrocephalum has a more elliptical-looking inflorescence than A. s. subsp. sandwicense, which is thicker (2).

Also known as
East Maui silversword, Haleakala silversword, Mauna Kea silversword, silversword.
Size
Leaf length: 15 - 40 cm (2)
Inflorescence height: up to 3 m (2)
Leaf width: 0.5 - 1.5 cm (2)
Top

Hawaiian silversword biology

These plants only flower once in their lifetime, the silver rosettes grow for a number of years before the inflorescence ascends skywards (3). Flowers appear from mid-June to November (2), and after the seeds have been shed the whole plant dies (4). These exotic-looking plants are ideally suited to their harsh environment; the silver leaves reflect the sun's rays whilst their shape prevents moisture loss and protects the more delicate centre of the plant from predation (4).

Top

Hawaiian silversword range

Endemic to Hawaii, Argyroxiphium sandwicense macrocephalum is found on the island of Maui upon the Haleakala volcano, whilst A. s. sandwicense is found on Mauna Kea on the island of Hawaii itself (2).

Top

Hawaiian silversword habitat

Inhabits alpine cinder deserts, on Hawaiian volcanoes at heights of between 2,125 and 3,750 metres above sea level (2).

Top

Hawaiian silversword status

Classified as Vulnerable (VU) on the IUCN Red List (1). Subspecies: Argyroxiphium sandwicense sandwicense classified as Critically Endangered (CR), and A. s. macrocephalum classified as Vulnerable (VU) (1).

IUCN Red List species status – Vulnerable

Top

Hawaiian silversword threats

These attractive plants were previously collected as curiosities; climbers on the mountains would dig them up as proof that they had reached the summit (5). Populations were further depleted by browsing and trampling by goats and cattle in the area (3). Today A. s. sandwicense is restricted to a single population of as few as 30 plants in the Wailuku River basin on Mauna Kea in Hawaii (2). These plants are at risk from the small size and range of their population, which is vulnerable to any chance event that might occur.

Top

Hawaiian silversword conservation

The Hawaiian silversword is protected in Hawaii; A. s. sandwicense is listed as Endangered by the U.S. Fish and Wildlife Service whilst A. s. macrocephalum is listed as Threatened (6). On the island of Maui, the silversword is found within the Haleakala National Park, which was designated as an International Biosphere Reserve in 1980 (7). The U.S. Fish and Wildlife Service has produced Action Plans for the conservation of each subspecies (6), and the Haleakeala silversword has shown encouraging signs of recovery since it was first protected in the 1930s (5). This species is one of the many rare plants and animals found within the lunar landscape of the Haleakeala crater and can act as an important flagship species for conservation in the area (6).

Top

Find out more

For more information on the Hawaiian silversword see:

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.ukTop

Glossary

Endemic
A species or taxonomic group that is only found in one particular country or geographic area.
Inflorescence
The reproductive shoot of the plant, which bears flowers.
Subspecies
A different race of a species, which is geographically separated from other populations of that species.
Top

References

  1. IUCN Red List (May, 2009)
    http://www.iucnredlist.org
  2. Wagner, W.L., Herbst, D.R. and Sohmer, S.H. (1999) Manual of the Flowering Plants of Hawaii, Vol. 1. University of Hawaii Press, Honolulu.
  3. Keck, D. (1936) The Silverswords of Hawaii. Carnegie Institution of Washington, News Service Bulletin, 4(8): 75 - 78.
  4. Islands – A Splendid Isolation(NHNZ tx. 1991).
  5. IUCN. (2001) The Red Book: The Extinction Crisis Face to Face. IUCN, Gland, Switzerland and Cambridge, UK.
  6. U.S. Fish and Wildlife Service (March, 2003)
    http://www.fws.gov/endangered
  7. Get Outdoors (May, 2009)
    http://www.getoutdoors.com/getoutdoors/destination_description/26.html

More »Related species

Eke silversword (Argyroxiphium caliginis)Kau silversword (Argyroxiphium kauense)Werneria (Werneria graminifolia)Pericallis (Pericallis malvifolia)Woolly camphor-weed (Pluchea ovalis)Stemmacantha (Stemmacantha cynaroides)Ayapana (Ayapana ecuadorensis)Pluchea (Pluchea obovata)

Please donate to ARKive today

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

Sign up to our newsletter

Get the latest wild news direct to your inbox.

Get involved

ARKive relies on its media donors to donate photos and videos. Can you help? There are plenty of other ways you can get involved too!

X
Close

Image credit

Hawaiian silversword in full flower  
Hawaiian silversword in full flower

© John Mason / www.ardea.com

Ardea wildlife pets environment
35 Brodrick Road
Wandsworth Common
London
SW17 7DX
United Kingdom
Tel: +44 (0) 208 672 2067
Fax: +44 (0) 208 672 8787
ardea@ardea.co.uk
http://www.ardea.com

X
Close

Link to this photo

ARKive species - Hawaiian silversword (Argyroxiphium sandwicense) Embed this ARKive thumbnail link by copying and pasting the code below.

Terms of Use - The displayed thumbnail 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.

X
Close

Terms and Conditions of Use of Materials

Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.

Visitors to this website (End Users) are entitled to:

  • view the contents of, and Material on, the website;
  • download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
  • teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.

End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.

Additional use of flagged material

Green flagged material 

Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.

Creative commons material

Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.

Any other use

Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.

Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.