The Hawaiian silversword (‘ahinahina) is a rare and endangered plant found only on Maui’s Haleakala and the Big Island’s Mauna Kea and Mauna Loa. It has adapted to the severe climate of its habitat, growing at altitudes of 5,000 to 10,000 feet. Scientifically called the Argyroxiphium sandwicense, it has thick rosettes of prickly leaves radiating outward from its base. These leaves are silvery pale green and nearly metallic in their appearance. The plant’s most stunning feature, though, is its 6-foot-long blossoms.
Many sword-like succulent leaves coated in silver hairs characterise the Argyroxiphium sandwicense subsp. macrocephalum. Plants of the silversword genus thrive on volcanic cinder, a dry, stony ground exposed to cold temperatures and strong winds. The skin and hairs of the plant are tough enough to withstand the wind and cold temperatures of this height whilst protecting it from dryness and the sun.
For the bulk of the plant’s life, the base of the leaves, which are grouped in a spherical configuration at the ground level, dominate. The leaves and their hairs have evolved to severe high-altitude temperatures by directing the sunlight to concentrate at this point and warm the plant, raising the temperature of the shoot-tip leaves to up to 20oC.
The silversword alliance is named after the silverswords, the alliance’s most well-known and physically attractive members. Three genera make up the clade’s species:
Wilkesia
Wilkesia is a Hawaiian plant genus belonging to the tarweed-silversword branch of the sunflower family. It has two perennials, both indigenous to the Hawaiian island of Kauai. Wilkesia is a Silversword alliance member named after Captain Charles Wilkes.
Argyroxiphium
The sunflower family, Asteraceae, has a tiny genus called Argyroxiphium. Because of its long, thin leaves and silvery hairs on specific species, its members are commonly referred to as silversword or greensword. Silverswords are part of a wider group of around 50 species that includes the visually distinct genera Dubautia and Wilkesia. The silversword alliance is the common name for this group.
Dubautia
Dubautia is a flowering plant genus in the Asteraceae family, including sunflowers. The genus as a whole is native to Hawaii. There are more species of cushion plants, shrubs, trees, and lianas in this genus than in the other two genera in the silversword alliance.
Conservation Hawaiian Silversword
It was given the Hawaiian name ‘ahinahina’, meaning ‘grey-grey’, yet ‘grey’ is simply too dreary a descriptor for a plant with such a metallic-shiny appearance. It gets its name from the tiny silver hairs that coat the surface of each leaf, apparently to shield it from the intense light and (often freezing) cold it experiences at this height.
It’s a member of the Asteraceae family, with succulent leaves grouped in a spherical form at ground level and a flower stalk rising from the centre.
The Argyroxiphium sandwicense is one of the Hawaiian Islands’ most spectacular conservation success stories. Human vandalism and feral ungulate grazing, which were formerly the most critical threats to the Argyroxiphium sandwicense, have been practically eliminated as a result of park management.
For both casual park visitors and evolutionary biologists, the Haleakala silversword is a beautiful, attention-getting animal. Continued protection from hoofed animals and human vandalism is critical, as is addressing potential threats such as the Argentine ant and exotic flora. Despite its limited distribution and complex life cycle, this species’ long-term survival prospects appear to be improving.
Haleakala Silverswords
The Haleakala silversword’s silvery hairs, succulent leaves, and low-growing rosette habit allow it to thrive in hot, dry regions like the crater’s aeolian desert cinder slopes. Silverswords have a lifespan of three to ninety years. They blossom once, bringing up a magnificent flowering stem, and then die quickly, spreading dried seeds into the breeze.
Conclusion
A rare Hawaiian plant is a silversword (Argyroxiphium sandwicense). It can only be found on Maui’s Haleakala and the Big Island’s Mauna Kea. In the volcanic mountains, it grows at a high height. The plant’s leaves are protected by a heat-reflective covering of white hairs. The silversword blooms only once, right before it dies. Silversword plants have a 12-year lifespan on average. Between June and November, the flowers bloom.