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.

Advertisement

18 thoughts on “Ohia”

  1. naturebackin

    What interesting plants. They vaguely remind me of some of our proteas but I looked them up and they are not even vaguely related. I did find that there is one Metrosideros species native to South Africa (in the fynbos biome) and it is regarded as an outlier. The plant being somewhat unfamiliar in SA and resembling other invasive aliens is often mistakenly identified and unappreciated, poor thing!

    Liked by 1 person

  2. Pingback: Sunday Stills: What’s #Bugging You? – Second Wind Leisure Perspectives

  5. kzmcb

    Clever tree, and beautiful flowers. The various directions for the roots points to a true survivor. I thought lava might be rich in nutrients, leading to huge trees and a mass of vegetation of all kinds.

    Liked by 1 person

    1. Graham Post author

      It is rich in nutrients and eventually, if there’s enough rainfall, it will be covered by abundant tropical foliage. Ohia is important because it can get established in the bare lava by drawing moisture from the lava tubes below ground.

      Like

    1. Graham Post author

      It has been very successful but is currently being attacked by a new fungus. Hopefully the trees will get though this and come back stronger than ever.

      Like

      1. BeckyB

        oh no that’s not so good – guess fungus has arrived from elsewhere

        And thank you so much for all the extra info in response to my comments on the actual pictures. I have learnt so much today 🙂

        Liked by 1 person

        1. Graham Post author

          Glad you enjoyed the post, Becky. There are two strain of the fungus and it’s known that they arrived from elsewhere, but where and how is not known.

          Like

    1. Graham Post author

      They’re a pretty tree, especially against the stark lava. They’ve been hardy too, but currently are under the cosh from a new fungus that’s killing a lot of trees.

      Liked by 1 person

Comments are closed.