Argyroxiphium sandwicense
| Kingdom |
Phylum |
Class |
Order |
Family |
| PLANTAE |
TRACHEOPHYTA |
MAGNOLIOPSIDA |
ASTERALES |
COMPOSITAE |
| Scientific Name: |
Argyroxiphium sandwicense |
| Species Authority: |
DC. |
| Infra-specific Taxa Assessed: |
|
Common Name/s:
| English |
– |
East Maui Silversword, Haleakala Silversword, Mauna Kea Silversword, Silversword |
|
Assessment Information
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| Red List Category & Criteria: |
Vulnerable
D2
ver 3.1
|
| Year Assessed: |
2003 |
| Assessor/s: |
Bruegmann, M.M. & Caraway, V. |
| Reviewer/s: |
Maunder, M. (Plant Conservation Committee) & Hilton-Taylor, C. (Red List Programme Office) |
Justification:
Although there is a large number of plants of this species, it has an extremely restricted range and could easily be impacted by the loss of pollinators (e.g., through competition with the invasive Argentine Ant) or by any other catastrophic event. Direct human threats are currently controlled within the National Park, but as visitor numbers increase, so those threats could grow.
|
Geographic Range
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| Range Description: |
Argyroxiphium sandwicense is endemic to the islands of Maui and Hawaii. Subspecies macrocephalum occurs on Haleakala on Maui, and ssp. sandwicense on Mauna Kea on Hawaii. There are eight subpopulations. The Haleakala subspecies is estimated to number 65,000 plants. The Mauna Kea subspecies, however, is down to about 41 naturally occurring plants plus a few thousand outplanted ones.
|
| Countries: |
Native:
United States (Hawaiian Is.)
|
Population
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| Population Trend: |
Increasing
|
Habitat and Ecology
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| Habitat and Ecology: |
These rosette shrubs are usually single-stemmed and rarely branched. A single-stemmed individual lives for a number of years (15–50), produces a terminal inflorescence, then dies (monocarpic). Plants with multiple rosettes produce one inflorescence for each rosette; flowering may occur over several years before all rosettes are exhausted.
Occurs in dry alpine desert; occasionally also in dry to moist subalpine shrublands and forests. Found on cinder cone slopes, cinder fields, lava flows, in rocky gulches, and on cliffs.
|
| Systems: |
Terrestrial |
| Major Threat(s): |
Threats include introduced sheep, goats, mouflon sheep, pigs, predation of native pollinators by alien wasps and ants (the species is self-incompatible and relies on insect pollination), overcollection, and in the case of the Mauna Kea subspecies, its small population size.
|
Conservation Actions
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| Conservation Actions: |
The Global Heritage Status Rank is G2 (=Imperiled). Both of the subspecies are included on the US Endangered Species Act.
|
