Argyroxiphium sandwicense ssp. sandwicense
The silversword, classified as an endangered species since 1986, is in the Asteracea or Sunflower Family. The Mauna Kea silversword is a member of the silversword alliance, a group of Hawaiian endemic plants that scientists believe all evolved from a single plant species that probably originated in North America several million years ago.
The Silversword gets its name from its leaves which are shaped similar to daggers and are covered with many layers of silvery hairs. The leaves grow in bunches called rosettes which can measure up to 2 feet in diameter. At maturity the Silversword produces a 6 foot tall flowering stalk with hundreds of flowers. Since silverswords sometimes grow for up to 40 years before flowering, it is relatively rare to see a silversword in bloom.
In the late 18th century ship captains visiting Hawaii intentionally introduced sheep and goats to the island. By the 1930s the feral ungulate population numbered around 40,000 animals on Mauna Kea. These feral sheep and goats eagerly browsed the tender leaves of the Mauna Kea Silversword, driving the plant to the verge of extinction.
Since the 1970s the State of Hawaii Department of Land and Natural Resources has eradicated many of the feral ungulates on the mountain, and begun reintroducing the Mauna Kea Silversword, first in fenced in exclosures similar to the one at the east end of the Visitor Information Station parking lot, and later in unfenced areas.