Readers’ wildlife photos

August 23, 2019 • 8:00 am

Today’s photos are from the Aussie Tony Eales, who gives all the notes we need:

A bunch of flowers today.

First is a weird member of the Showy Mistletoe family, Loranthaceae, called Amyema cambagei or the She-oak Mistletoe. Mistletoes including this species often display host-mimicry that is often so good that were it not flowering, it would be difficult to notice the plant. The long needle-shaped leaves of the mistletoe is a near perfect match for those of the Casuarina and Allocasuarina trees that it parasitises.

Next are three mangroves but the first mangrove isn’t a mangrove. Aegiceras corniculatum is called the River Mangrove and is in the Primrose family.

The next two are actually members of the mangrove family Rhizophoraceae. Bruguiera gymnorrhiza is called the Orange Mangrove and Ceriops australis the Smooth-fruited Yellow Mangrove [JAC: in order below]. All these trees have amazing adaptations to the dynamic and saline habitat that they help create along the shorelines.

Next is Persoonia virgata; I just love its flowers, as they look a bit like tiny bananas as they open. On the eastern side of Australia where I live, the genus is known as Geebungs, but in the weird west they are known as Snottygobbles. Yuck. I’ve never tried the fruit; I seem to only find unripe fruit in the bush but I suspect it’s quickly snapped up by birds when it ripens.

The last three photos are of Triggerplants. Triggerplants are a mainly Australian genus with an amazing method of pollination. When an insect lands on the flower a trigger that was bent back behind the plane of the flower, springs up and covers the insect in pollen. They are also unusual in the floral spikes and sepals often being covered in sticky trichomes similar to those of a sundew which can trap insects. This has led some to conclude that they are proto-carnivorous but that is disputed. The bright pink ones are Stylidium graminifolium, which grow in a grassy rosette of leaves from which a tall spike  that can be up to 60cm or longer. You can see some with sprung and unsprung triggers and make out the trichomes in one of the photos.

The other is photo shows two flowers of Stylidium repens from Western Australia, on a tiny plant only about 5cm tall. In this photo the flower on the left has been triggered and the one on the right is still set.


15 thoughts on “Readers’ wildlife photos

  1. Just such a beautiful bunch of flowers and photographs of them.
    I’ve never seen anything like the Persoonia virgata. It’s a gorgeous photo.
    Thank you for sharing.

  2. Beautiful.
    If the Triggerplants’ sticky trichomes … can trap insects it seems to need an explanation. If they don’t benefit the plant by being proto-carnivorous they’d reduce pollination and thus work against survival. That can’t happen, can it?

    1. It can most certainly happen, as evolution is not an optimising algorithm, and not every feature is an adaptation. But in this case it is suspected the trichomes are probably adaptive. The two main ideas are that:

      1/. the trigger plants mostly occur in low phosphate environments. The trichomes trap insects, which die and then rot on or near the plant, increasing the locally available phosphate.

      2/. The trichomes ability to trap insects protects the plant from insect predation.

      It is also possible that they are preserved because they do a little bit of column a, a little bit of column b.

      As yet we haven’t been able to unambiguously distinguish between the above cases. Or at least we hadn’t about 5 or 6 years back when I last looked up this stuff.

  3. Very beautiful flower photos. Thanks for the in-depth commentary as well. And I appreciated the two ants. 🙂

  4. Very nice photos. Thank you for sharing. Interesting to see mangroves from other parts of the world. In the eastern U.S., we have three mangrove species, but mangrove isn’t used in a taxonomically restrictive manner. Rather, it refers to those tropical trees with adaptations to living in coastal waters. Each of the three is in a different family of plants. I’ll try to find some photos, if there’s interest.

  5. The host mimicry in the mistletoe is intriguing. Some have suggested that the mistletoes evolve mimicry to hide from local possums that eat them. It could also be natural selection from specialized herbivorous insects that use leaf shape to find their mistletoe food-plants.

  6. Interesting that Persoonia virgata is known as snottygobble in the West. In SA the native parasitic vine Cassytha pubescens is commonly known as snottygobble. It’s kind of topical at the moment. It looks like it may be a useful biological control for introduced gorses.

    Nice shots. I particularly enjoyed the trigger plants.

    1. I think the SnottyGobble name gets applied rather loosely and I’ve seen it applied to various parasitic plant fruits but I read it was an alternative for Geebung in the west on Wikipedia

Leave a Reply