Scientific Name
Argyroxiphium sandwicense DC.
Common Names
Hawai'i Silversword, Hawaiian Silversword
Synonyms
Argyroxiphium sandwicense var. sandwicense, Argyroxiphium sandwicense subsp. sandwicense
Scientific Classification
Family: Asteraceae
Subfamily: Asteroideae
Tribe: Madieae
Subtribe: Helianthodae
Genus: Argyroxiphium
Description
Argyroxiphium sandwicense is a low-growing plant having rosettes up to 2 feet (60 cm) in diameter of narrow, pointed, silver-green leaves and clusters of profuse red-purple flowers on a up to 10 feet (3 m) tall stem. It flowers only once in its life of 20 to 90 years.

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Hardiness
USDA hardiness zone 10a to 10b: from 30 °F (−1.1 °C) to 40 °F (+4.4 °C).
How to Grow and Care
The silversword alliance is a group of about 50 species of plants belonging to three genera endemic to the Hawaiian islands. They get their common name from the visually impressive silversword.
These plants only flower once in their lifetime, the silver rosettes grow for a number of years before the inflorescence ascends skywards. Flowers appear from mid June to November, and after the seeds have been shed the whole plant dies. 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 center of the plant from predation.
These attractive plants were previously collected as curiosities. Climbers on the mountains would dig them up as proof that they had reached the summit. Populations were further depleted by browsing and trampling by goats and cattle in the area. Today Argyroxiphium sandwicense is restricted to a single population of as few as 30 plants in the Wailuku River basin on Mauna Kea in Hawaii. These plants are at risk from the small size and range of their population, which is vulnerable to any chance event that might occur.
The Hawai'i Silversword is protected in Hawaii.
Origin
It is endemic to Hawaii (found on the mountain Mauna Kea on the Big Island at elevations above 2,600 meters).
Subspecies, Varieties, Forms, Cultivars and Hybrids
Links
- Back to genus Argyroxiphium
- Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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