There’s a fungus on the Town Hall Clock!

If you’ve read my latest post you would know that I am a regular participant of #wildflowerhour. During last week’s Wildflower Hour there were predictably more photos due to the increase in flowering plants as spring progresses. Among these flowering plants was the easy-to-overlook Moschatel (Adoxa moschatellina), which I had never recorded before.

So last week I set out with a picture of Moschatel in my mind so that if I did come across the species I would recognise it. Yesterday I visited Pulborough Brooks RSPB reserve in West Sussex and I did both of those things: I came across a couple of large patches and I recognised it!

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The flower head. You can see that it is cube-shaped, which is what lead to the alternative vernacular name of ‘Town Hall Clock’.

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The whole plant

As you can see from the above photographs, Moschatel is not a hard plant to miss. Its flower heads are only slightly lighter than the leaves and therefore not easy to spot when they are lined up against the foliage of a woodland floor. To be honest, I was quite pleased with myself for managing to spot this indistinctive plant!

However once I had a closer look, there was more to see. One particular patch was very heavily infected with what appeared to be the fungus Puccinia albescens, which covered the leaves, stem and flowers of several plants. This species is a rust fungus, which is a type of fungus that usually parasitises wildflowers and other small plants. There is an incredible diversity of host plants within the 7000 species of rust fungi as most plants are only infected by a single species.

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The close-up photograph above shows the pustules of the rust fungus, which is just one part of the complex life-cycle of rust fungi. These pustules erupt at this time of year and produce uredospores which are carried on the wind to new plants of the same species to infect.

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Telia

Also present alongside these pustules are what I believe to be the telia of the same species. These telia – the dark, round spots – are produced in the autumn in most species and would have overwintered. The telia produce teliospores, which are another method the fungus uses to spread as they disperse to find more plants of the same species to infect, just as the uredospores do.

The life-cycle of rust fungi is very complex and here I have explained it only briefly – different species of rust fungi can have different life-cycles and some infect two completely unrelated species during their life-cycle. These multi-host fungi are known as heteroecious fungi and one host plant is infected by the uredospores and the other is infected by teliospores. As Puccinia albescens is not heteroecious (and is autoecious), its life-cycle can be completed on just a single host species – Moschatel – and the single host species is infected by both the uredospores and the teliospores. Some good websites to visit for more information on the life-cycle of rust fungi are:

http://www.biologydiscussion.com/fungi/life-cycle-and-the-spore-stage-of-rust-fungi-fungi/64083

http://website.nbm-mnb.ca/mycologywebpages/NaturalHistoryOfFungi/Pucciniales.html – this one includes a lot of information, however it also contains a lot of scientific jargon and complicated vocabulary.

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An Insight into Daphnia biology

Daphnia are truly amazing. They are often called ‘water fleas’ as they look like tiny fleas swimming around in lakes and ponds. However, they are harmless and fascinating to observe. You can easily find some at home – just scoop a bit of water out of your pond with a pot and hopefully there’ll be plenty of these complex organisms bobbing about!

Believe it or not, Daphnia are actually tiny crustaceans, related to crabs, lobsters and woodlice. The reason they don’t look very similar is that the shell of Daphnia is uncalcified (not hard). This means they’re see through, and so great to put under a microscope. Yesterday and today I collected a few Daphnia from the pond with my pipette (like a small turkey baster), put a drop of water containing the Daphnia on a microscope slide and placed a cover slip gently on top so that the Daphnia wouldn’t be squashed.

Looking at them under a microscope reveals a whole new view on their lives, which we could never see with the naked eye. This photo I took yesterday and I find it most intriguing, Daphnia obtusa giving birth!

Daphnia giving birth!

Daphnia giving birth!

In the photo you can make out a smaller version of the adult Daphnia just below it’s rear end, at the bottom. Look for the black eye. To add to that, as the Daphnia is see through, you can also see its twin still inside the adult!

With the Daphnia collected today, I could also see their tiny heart beating. This short video I recorded shows it well:

To help give an idea of where the heart is on a Daphnia, this is the image of the pregnant Daphnia with most of its anatomy labelled:

Simple Daphnia Anatomy

Simple Daphnia Anatomy

The antennules – These are antennae, but instead of being sensory organs, they have evolved to be used to propel the Daphnia through the water. The ‘proper’ antennae are found beneath the rostrum, and are tiny. The mound on which the ‘proper’ antennae are born, sensibly called the antennal mound, is an important identification feature of Daphnia obtusa and is just visible in the image above. Daphnia obtusa has a noticeably larger antennal mound than similar species like Daphnia pulex.

I hope you’ve enjoyed this post on Daphnia. Hopefully this has inspired you to look for Daphnia in your own local pond or lake. Daphnia are incredibly unrecorded for such an abundant animal, which is probably present in nearly all squares in the UK:  >>CLICK<<