Tag Archives: Ohia

Ohia

  • Ohia trees growing in the lava
    Ohia trees growing in lava
  • Ohia trees growing in the lava
    Ohia trees growing in lava
  • Ohia roots growing down into a lava tube
    Ohia roots growing in a lava tube
  • Ohia roots growing aerially
    Aerial toots

This week’s Sunday Stills challenge theme is ‘Geometric–explore various angles.’ I’ve focused more on the ‘various angles’ than the geometric.

Ohia trees (Metrosideros polymorpha) are endemic to Hawaii and the flower of these trees is the official flower of the Big Island. Depending on growing conditions, ohias can vary from ground hugging shrubs to 50 foot trees. They grow at sea level and at elevations up to 8,000 feet. They’re probably most noted for two things. One is their brilliant display of flowers. The other is that they’re usually the first plants to recolonize lava flows.

They grow in lava is because their roots reach down into lava tubes and tap into the moisture available there. But ohia can also put out aerial roots to gather moisture. They’re very flexible in this way.

  • Ohia flower buds
    Buds form
  • Ohia flower buds begin to reveal the flower within.
    Stamens emerging
  • An ohia flower
    An ohia flower

The puffball flowers are actually clusters of flowers. Each flower is made up of a bunch of stamens (the male part of the flower) and a single pistil (the female part) which is thicker and longer than the stamens. When the flowers have been pollinated, the stamens fall away until only the pistil remains. This too will disappear as the calyx, where the seeds are found, develops. Eventually, the calyx will dry out and release the tiny mature seeds, to be dispersed by the winds, and hopefully grow into new ohia trees.

  • An ohia flower after pollination
    The stamens fall off…
  • Ohia flowers after pollination
    … until only the pistils remain.
  • Ohia seeds develop as the plant dries out,
    The calyx dries out…
  • Ohia seeds develop as the plant dries out,
    … Ready to release seed
  • Different stages of ohia flowers can be seen on a tree at the same time

Also posted in response to Becky’s July Squares challenge theme of ‘Trees.’ See more responses here.

Halemaumau Crater

A view of Halemaumau Crater and Jaggar Museum in Hawaii Volcanoes National Park

The latest eruption at Kilauea Volcano has recently been declared paused. It was never an especially dramatic eruption, but when I went down a few days after it began (here) the sky was illuminated by the activity. In recent weeks though, the lava lake formed by the eruption crusted over completely and lava from the active vent was also hidden from view.

The photos are two views of Halemaumau Crater, taken before this latest eruption. In the top one, the collapsed floor of the crater is on the left. This is what the new lava lake was filling up. On the ridge, to the right side of the photo, is the low profile of the Jaggar Museum, which was closed after the 2018 eruption and likely won’t reopen.

The bottom photo shows the easternmost edge of Halemaumau Crater, which wasn’t greatly impacted by this eruption or the events of 2018. Consequently, the walls of the crater are quite green and the floor is dotted with plants. These plants are mostly ohia trees, which are among the first plants to grow in lava fields, in part because their roots will tap into lava tubes to find moisture and nutrients.

For more information about Hawaii Volcanoes National Park and Kilauea’s eruptions, go to nps.gov/havo/.

A view of Halemaumau Crater from the Byron Ledge Trail in Hawaii Volcanoes National Park

Part of Crater Rim Drive in Halemaumau Crater

Halemaumau Crater, at the summit of Kiluaea Volcano, underwent profound changes during the 2018 eruption. When lava drained from the summit vent, the crater floor experienced a series of collapses, radically changing the appearance of the crater and its surrounds.

I had seen this area from the air and posted about it (here). The middle photo was taken during that flight and shows where a section of Crater Rim Drive slid into the crater. When I last visited the park, I got a different view of this.

The recently reopened Byron Ledge Trail has good views across the crater. In the top photo, the chunk of road is clearly visible with its white line running down the middle of it. The bottom photo shows the longer view across the crater with the road in the distance. In the center of the photo, equipment used to monitor the volcano’s activity, can be seen. The tree in the foreground is an ‘ōhi‘a lehua with its brilliant red flowers. It’s an early colonizer of new lava flows and all those little dark spots on the main crater floor are ‘ōhi‘a lehua trees, mostly still shrub-sized at this time.

Ohia Lehua flower

This week’s Sunday Stills challenge theme is ‘Country or State Flower.’ See more offerings here.

The country flower for the USA is the rose and I don’t have photos of those. The state flower for Hawaii is the hibiscus and, while I have lots of those, they’re all of Chinese hibiscus (Hibiscus rosa-sinensis). The state flower is the native yellow hibiscus (Hibiscus brackenridgei) and I have none of those. The native hibiscus is not often seen in the wild and is currently considered an endangered species, but it is used as an ornamental in domestic gardens.

Having struck out on the two proper responses to this challenge, I’ve chosen to post photos of the official flower of the Big Island, the red ʻōhiʻa lehua (Metrosideros polymorpha). A member of the myrtle family, ʻōhiʻa lehua is endemic to Hawaii. It’s one of the first trees to colonize lava flows. It’s able to survive in such a tough environment because its roots grow down into lava tubes and other voids in the lava and tap into the moisture there.

Recently, ʻōhiʻa trees have been attacked by a fungus which can cause the trees to die within a very short time. This disease, known as Rapid ‘Ohi’a Death, is caused by two new types of Ceratocystis fungus.

The Nāpau Trail – Over the lava

A surface lava flow on Napau trail.
An early part of the trail follows a surface flow down the side of a hill with a small ohia tree toughing it out in the lava.
A lava channel on Napau trail.
In a couple of places the trail goes through sunken areas that channeled the lava.

The Nāpau Trail in Hawaii Volcanoes National Park, is a 13-mile round trip. It passes over extensive lava fields, plunges into dense forest, and ends at the Nāpau Crater overlook. The overlook offers a terrific view (weather permitting) of Puʻu ʻŌʻō, one of two active vents on Kilauea Volcano. In today’s post I’m going to cover the lava fields portion of the hike with the second part coming tomorrow.

From the Mauna Ulu parking area, the first mile or so is a well-trodden trail to Pu’u Huluhulu (hairy hill) cinder cone. The foot of Pu’u Huluhulu is where the Nāpau Trail branches off across the lava. It’s a stark landscape, but with lots of interest. The trail passes over surface flows and through channels where lava rivers ran.

The Park’s website notes that the Nāpau Trail “follows the path that magma takes as it makes its way underground from its source at the summit to the point where it comes to the surface near Puʻu ʻŌʻō.” The many steam vents around Mauna Ulu are testament to this.

And in this hostile landscape, nature is at work. The lava fields are dotted with tenacious plants establishing a toehold.  Ohia trees and ferns are most frequently seen, but grasses and other plants lend color to this sea of gray and black.

It’s 2.2 miles of unbroken lava from the Pu’u Huluhulu junction to the rim of Makaopuhi Crater, but at that point the trail changes in an almost surreal way. I’ll post that section tomorrow.

For more information about this, and other hikes on the Big Island, go to bigislandhikes.com.
For more information about Hawaii Volcanoes National Park, go to nps.gov/havo/.
For more information about Kilauea Volcano and it’s eruptions, go to hvo.wr.usgs.gov/kilauea/history/main.html.

Steam vents on the eastern side of Mauna Ulu.
Steam vents on the eastern side of Mauna Ulu.
Cairns mark the route across an ocean of lava toward Makaopuhi Crater.
Cairns mark the route across an ocean of lava toward Makaopuhi Crater.
Looking down into Makaopuhi Crater.
Looking down into Makaopuhi Crater, which most recently erupted in 1972.