IfA Hilo Outreach - Koa's Resources
The Jewel of Mauna O Wakea: Silversword (`Ahinahina)
"On the chilly high slopes of Hawai`i's Mauna Kea volcano grows a plant that bears in its genes the patience of the ages" (NWF)
The Mauna Kea Silversword, known as `ahinahina in Hawaiian, is the prized plant of the mountainside. Famous for its beautiful silver color, its presence allows for the perfect contrast to the drab mountain landscape. Although it is still rare to come across one of these treasures, they are making a come back and soon this species will return to its natural brilliance.
Botanists have determined that the ancestors of the Hawaiian silverswords came to Hawai'i about 5.2 million years ago based on carbon dating. These ancestors formed 30 species of silversword, collectively called the silversword alliance. The two most closely related species are the Mauna Kea and Haleakala silverswords.
Silversword plants need the pollen of another silversword in order to produce fertile seeds. This means that silverswords cannot reproduce by themselves, they need help from insects called "pollinators". Pollinators act as a carrier for the silversword, much like a mail carrier, picking up pollen at one plant and dropping it off at another. The native yellow-faced bee is the main pollinator of the Mauna Kea silversword (Oboyski).
The Mauna Kea Silversword is a rosette shrub protected by the Endangered Species Act since March 21, 1986. The characteristic silver, dagger-like leaves inspired the name silversword. The flowering stalk has sticky hairs on the green leaves, stems, and central stalk, which happen to attract insects.
The Circle of Life
The young plant grows for 20-50 years, storing up enough energy to move on to the next stage. During this time, it can develop rosettes up to two feet in diameter. Occasionally, there will appear to be a cluster of rosettes "branching" from a central rosette.
After the flowers bloom, they are pollinated by several insects. The silverswords leaves ripen in about three months and are dispersed by either wind or water. The adult silversword dies once its seeds are released onto the surrounding land. Branching is one benefit for the silversword because only the flowered branch will die, not the whole plant.
Habitat: Volcanic cinder soil 19.5 inches-31.2 inches (50 cm-80 cm) annual rainfall 8,528 feet-12,464 feet (2,600m-3,800m) elevation, 51.8 degrees F (11 degrees C) annual mean temperature.
* Download this document
NOTE: A visit to the Mauna Kea Visitor Information Station's Silversword exclosure to see the replanting program may be arranged for your educational group.
This special tour may be a part of a package that includes a Hawaiian protocol at the VIS exclosure and multimedia slide show at the VIS presentation room. Reservations are dependent upon available staffing and schedule. Please call 932-2399 for more information