Hawaii

November 5-28, 2011

hawaii - november 8

Haleakela Sliding Sands Trail

Sliding Sands Trail - Part 2

Once we got back on the main trail, we started to see more and more silverswords. About 90 percent of Haleakala's native flora (some 370 species) are found only in Hawai'i. Adaptation over millions of years in isolation from their mainland ancestors has resulted in many bizarre and beautiful forms, such as this silversword group.

The Hawaiian name for the silversword is 'ahinahina. Hina means "gray" and repeating it twice means "very gray" (ie. silver!). The Haleakala Silversword is a member of the Silversword Alliance, a group of about 30 plant species throughout Hawaii, which are believed to have evolved millions of years ago from tarweed plants in California. These tarweed seeds floated over 2000 miles on the open ocean to colonize the Hawaiian islands. Both silverswords and tarweeds are members of the sunflower family.

Silverswords have adapted to their dry environment by storing a large amount of water in their thick leaves. As the flowering stalk grows, it pulls water from the leaves and they begin to droop. They have adapted to their cold environment by building themselves a reflector oven. Their leaves are covered with shiny silver hairs, and are curved into a parabolic shape that focuses the warm sunlight on the plant's growing point. This can raise the temperature of the growing point by up to 40 degrees F.

In some areas you can see how a crust of cinder ash and stone has formed along the sides of the Haleakela crater.

A popular (but more expensive!) way to discover the Haleakela crater is to take a horseback riding tour into it.

Luckily we wouldn't be seeing too many of these... bye, bye horsies!

We're getting closer to the crater floor now.

The kids next to a baby silversword.

A baby silversword up close.

Given that it wasn't supposed to be the right time of year to see silverswords in bloom, we were very excited to find this one!

Silverswords live for about 10 to 50 years as a low, round bush. At the end of their life,
they send up a flowering stalk that can grow over 6 feet tall within a few weeks, and produce up to 600 flower heads.

We ended up calling them the hula flowers since they looked like they had swaying hula skirts on!

As the flowers shrivel and fall off only the silvery stalk with the bottom leaves remain which look like a silver sword (hence the plant's name).
This one is almost ready to fall over.

As we went further we saw more and more of the silverswords...

...what an odd plant in such an odd landscape!

'Ahinahina (the hawaiian word for silversword) has a dense covering of silvery hairs to conserve moisture and protect the plant from high-elevation sun.

A helicopter tour in the distance... the helicopters are not allowed to fly directly over Haleakela crater.

These looked somewhat like pearly everlastings.

Can you spot the bug? From a distance the cinder desert appears devoid of life. But down in the basin unusual species of plants, birds, and insects -
often hidden among the rocks - have adapted to the summit's extremes.

A ladybug.

We were careful not to walk up too close to any of the silverswords or to get off the path...
silversword seedlings are very sensitive to soil compaction from footsteps.

As we travel along the crater floor the path becomes more like a ditch!

It's starting to feel like we're on the moon!

Lava rock sculptures.

Bubble rocks!

The silversword's habitat is at an elevation of 7000 - 10,000 ft, in soil composed of volcanic cinders.
The weather at this height is very dry, sunny, windy and cold.

At one point we came across this beautiful silversword where the flowers were still fresh...

Taking a break to admire the silversword.

silversword

The Haleakala Silversword is a threatened species. It used to be threatened by overzealous tourists and grazing cattle but the National Park now keeps these under control. What threatens the silverswords today is an invasive species of ant from Argentina, which is preying on the native insects that pollinate the silverswords. Since silverswords flower only once in their long life, this small window for pollination is critical to their survival.

Here you could see the resemblance to the sunflower family in the blossoms.

The only place silverswords are found in the world is within a 250 acre area on Mount Haleakala, on the island of Maui in Hawaii.
And we got to see it in bloom. :)