Dandelions and Apomixis – or no need for sex!

 

Apo –what? Read on and you will have a new word to add your vocabulary.  In a previous post I wrote a little about dandelions. It is fairly easy to name a plant as a dandelion but it is very tricky to identify the particular kind of dandelion or micro species. There are very few experts who can confirm an identification and act as referees. The main referee is the man called John Richards who wrote the definitive book on identifying UK dandelions.

One of my Christmas presents was a new book by John which is full of colour photographs should hopefully make it easier for us learners. 

The reason that dandelions are so hard to pin down is that there are hundreds of micro species with slightly different characteristics. These characteristics persist from generation to generation because dandelions can produce seed without being pollinated. This means that every seedling is a clone or identical genetic copy of its parent. The scientific name for being able to produce viable seed without pollination from another plant is called ..... apomixis.

Recent research using dandelions has discovered the gene that allows apomixis. They have called it PAR which is short for parthenogenesis which means virgin birth. Here is a quote explaining how it works:

Egg cell fooled
A group from Wageningen University & Research was also involved in the study and showed that the PAR gene is normally inactive in egg cells. The PAR gene normally only becomes active in the egg cell after fertilization, it then divides to create a plant embryo. In the egg cells of dandelion plants that form seeds via apomixis, the PAR gene proved to be switched ‘on’ prior to fertilization. In other words, these egg cells ‘think’ they are fertilized and start dividing without fertilization has taken place.

There is also a video here.

This bit of research might seem to have no practical application but in fact the ability to produce identical plants from seeds would be an agricultural goldmine. Gardeners among you know that buying F1 seed is expensive because each generation has to be produced by cross fertilising two different plants to produce the hybrid. If the hybrid plant was modified to contain the PAR gene then it could produce seeds that were identical to be original plant. Researchers have already managed it with sunflowers and lettuce However there are also drawbacks to having every plant identical as any diseases will attack all of them. All the bananas that we buy are actually the same genetically and there is a real risk of the worldwide population of the Cavendish banana being wiped out if a new disease takes hold.

Owls, Voles and Bones

 I have become more interested in bones since I broke my ankle and got to look at the X-ray:

My ankle is now held together with various bits of metalwork.  I had mistakenly thought that my ankle was made up of several separate bones but it looks as though most of it is the ends of your leg bones and the big bone that forms your heel.

Over the past year, I have found several owl pellets. Some were on the balcony area of our shed, and some were found on boulders up Glen Banchor.  Both places are where owls can perch and digest their catch. Owl pellets are made up of the non-digestible parts of their food and are regurgitated as pellets of fur and bones.

Dissecting an owl pellet is probably the closest most of us will get to being a forensic pathologist and doing a postmortem!

Owl pellets - some intact (top right) and some starting to disintegrate (on left)

Some I could identify such as the pelvic bone bottom left.

Pelvic bone with the pin pointing to the  round socket (for the ball of the leg bone (femur) to fit in)

 The skulls are made of very thin bones which fragmented but I did find one almost complete skull.

Skull

The jaw bones tended to survive best, and the teeth patterns provide a way of identifying what creature was eaten. 

Upper jaw

Tooth pattern

I think most of the remains were from Field Voles. My dog regularly catches Field Voles when out on a walk and unfortunately some also make their way into the house and get caught in the mouse trap.

Occasionally I see evidence of Voles in the garden - a hole and leaves under a flower tub or once I saw two fighting and squeaking  (at least I thought they were fighting - maybe it was something more romantic?)

Mistletoe

As I am confined to home for the next few weeks while my ankle heals,  I decided to write a post about a Christmas plant.  Mistletoe is often hung inside houses at Christmas and the tradition is that if you meet someone underneath it, then you kiss, (though I am not sure if this is allowed in Covid times!)  

Mistletoe (Viscum album) does not grow locally as this distribution map from the BSBI website shows:

It is most common in southern England and I have seen it on apple trees in the South West and very abundantly near London, in Bushy Park (by Hampton Court) where the trees are liberally festooned with round green clumps, which are easily seen in the winter when the trees are bare. It is spread by birds eating the white berries which leaves their beaks sticky and they wipe off the sticky seed onto a tree branch where it might grow.  Mistletoe is semi-parasitic, depending on the tree for nutrients but also able to photosynthesise as it has green leaves.

Mistletoe features in Norse myths, which is surprising as it does not seem to like Northerly districts and only grows in Southern Scandinavia. One story says that the mischievous god Loki used mistletoe to kill Baldur when all other plants had sworn not to harm him.

If you are interested in Norse Myths, there is a dramatisation of Neil Gaiman's Norse Mythology on Radio 4 on Christmas Day 2021 and it will be available for a short time afterwards:

https://www.bbc.co.uk/programmes/m0001rjt 

Dangerous Lichen Hunting?

 In my quest to improve my lichen knowledge, I joined a Zoom beginners course and after it was finished, our small group continues to meet by Zoom fortnightly to discuss whatever lichens we have seen. The last time, we talked about a group of lichens called Stereocaulon.  These are small (aren't they all!) grey bobbly lichens that grow on rock or soil.

I found quite a large population on a rock near Shepherd's Bridge. This bridge is at the end of the tarmac road which goes about 2 miles up Glen Banchor from Newtonmore Village.  There is a car park at the end which is well used by walkers.  There is a stone saying "Dalchurn" which is the anglicisation of the Gaelic name of Place of the Rowans but most people still call it Shepherd's Bridge. It is a popular spot  for swimming in the summer, though every year the path alongside the burn gets more heavily eroded and undercut and it is only a matter of time before it disappears altogether and we will have to use the alternative route along the top of the escarpment which drops steeply to the swimming spot.

Looking downstream with the swimming spot off to the left.

Looking upstream at the confluence of the burn that goes under Shepherd's Bridge with the Calder

Two weeks ago, I wanted to take more photos of the Stereocaulon.  It rained heavily but after lunch the rain stopped and at 2.30 I decided to take the dog for a walk while I found the Stereocaulon again. It gets dark quite early now so I took the car and parked at Shepherd's Bridge then took the upper route down to the river and safely negotiated the steep path down.  There was  one last change in level, and I thought it looked a bit slippy so took it carefully.  A fateful move.... the next thing I knew I was on my bottom on the grass below, my legs stretched out in front of me and the ominous sound of a crack.  Looking down, my right ankle was at a very strange angle and I knew I had probably broken it. The ankle waggled on my leg as if no longer connected. Taking out my mobile phone to ring for help, I found there was no mobile signal. What now? No one knew exactly where I was, just "up the Glen" and it would be dark in an hour.

I decided there was no point in staying put and started to crawl on my hands and knees back up to the path that lead back to Shepherd's Bridge.  It was wet and bestrewn with sheep droppings but surprisingly I was not in pain. Just before I got to the narrow part of the path I saw some walkers across the river and blew my dog whistle, 3short blasts 3 times.  All that achieved was that the dog came back! I am sorry to say that Jeff the dog is so used to me being on my hands and knees looking at plants that he did not think there was anything amiss. Another set of blasts with the whistle and hurray - the walkers looked over and responded to my cry for help and came to my rescue.  What a relief to have company! There was a faint mobile signal so I rang my husband who rang the emergency services.  Not straightforward as they are now based in Glasgow and did not seem to have any idea where Newtonmore and Glen Banchor were and kept asking for the road and house number! Anyway, while we waited for the ambulance, a friend brought a thick jacket and dog blanket, and drove my car home with the dog. Mark turned up in the spare car fortuitously picked up from our son that week for us to keep while he went abroad. The Kingussie ambulance service turned up and the lovely Rona-Mae cut off my (new) jeans and my walking boot and splinted my leg. Her colleague had some gas and air which was welcome by now as it had started to hurt.

Looking at the narrow undercut path, they did not think they could get me out that way so alerted the Mountain Rescue team. However, the keeper Jimmy Grant, had been up the hill shooting deer and was parked at Shepherd's Bridge so when he arrived, he was drafted in to help.

I hopped to the Argo and with Rona holding my leg we were back at the car park in a matter of minutes. I can see from the photo that it was starting to hurt at this point!

Once at Raigmore (the hospital at Inverness), I was very lucky - no queue for A&E - and I was soon X-rayed, a temporary cast put on, and operated on the next day. The treatment by NHS staff was superb. I am now back at home with a cast on my leg and metal plates in my ankle, so any blog posts will be of old walks and photos as I will not be out and about for a while.

Oaks and Acorns

 For the first time, I have noticed plenty of acorns on the oaks trees that I have seen alongside the Calder on the Wildcat Trail, and on a walk on Kinrara Estate (near Aviemore).  Thirty years ago, my daughter wanted an oak tree for her birthday and we looked in vain for some local acorns in the woods at Kincraig but failed to find any that year. We bought a sapling and it is still growing in the garden - and it is her birthday today...

Oaks at Kinrara

There are two kinds of common oaks (there are actually lots of kinds of oak but let's keep it simple!) called the English Oak (Quercus robur) and the Sessile Oak (Quercus petraea).  The latter is more common in the North.  The word "sessile" means seated and when used about a plant it means that there is no stalk or a very short one.  Confusingly, the sessile part of the name  in Sessile Oak does not refer to the leaves, but to the acorns - it has acorns that sit on the twig, but leaves that have a stalk. Whereas the English Oak has acorns with a stalk and the leaves are sessile! I must admit that I find it hard to judge between them from that characteristic. Perhaps an easier way is to look at the shape of the leaves. The Sessile Oak has wavy lobes whereas the English Oak leaves are a bit irregular. I think most of what I see is the Sessile Oak but apparently there is quite a bit of variation with the leaves like one sort and the acorns like the other! So maybe is it not surprising that I get confused. However, they are lovely trees to look at, whatever their name.

The bark on the thick trunks was quite furrowed and when I went for a closer look, there were greener patches with tiny black dots.

The furrowed bark (with a hand for scale!)

The little black dots turned out to have tiny stalks, like little nails.

This is not a fungus but a pinhead lichen called Calicium viride  which is common on oaks.  It was the first time I have found it. 

 I also found a dead leaf with a white "pearl" on it. This is probably a gall caused by an insect such as an oak gall wasp and the larva develops inside and makes the tree grow these strange structures.

I assumed it was long dead and cut it open - but there was a larva inside (oops).

There is another gall called the Oak Apple Gall which is a bigger brown sphere, and was used in the past to make black ink that was used on medieval manuscripts.  There is a great video by the British Library showing how it is made here.

When is a fungus not a fungus?

Dog Vomit, Wolf's milk... there are some very imaginative names for things that look like a fungus.  But appearances can be deceptive.  Here is an example of something I saw whilst walking round Loch Imrich (Newtonmore) yesterday. It was growing on a rotting tree stump and although it was quite small it was an startling colour:

The tree stump

Getting closer

A closer look showed it was made up of lots of small fingers and looked a bit like a sea anemone or coral. My guess is that this is a slime mould.  These are fascinating organisms which are neither plant nor fungus but single celled organisms which spend most of their lives separately and invisible to the naked eye, but then come together when there is plenty of food available and produce these fruiting bodies like the one in the photo.  Soon it will change its appearance and produce spores ( I might go and have a look tomorrow!).  Looking at photos online, this one might be Tubifera ferruginosa, Raspberry slime mould.

I think I found the Dog Vomit slime mould in the woods by Wolftrax - another startlingly bright colour.

I did go and look at the Loch Imrich slime mould again and it has now changed to a muddy brown. I assume it will be releasing its spores soon.

Slime moulds have fascinating behaviour. Although they have no brain, collectively they can solve mazes in search of food, and can learn. You can read more about them here and see some amazingly beautiful photos of them here

And there is even a video from the BBC here

Fruits, fungus and flies

 Autumn is coming at last, after what has felt like an extended summer with no frosts yet.  Some of the birch leaves ae turning yellow and many of the plants have gone to seed or are bearing fruit.  This post will be heavy on photos as I have been capturing some of the different fruits I have seen locally.

But before then, a bit more on the fungus I mentioned in my last post (Amanita crocea). One of the toadstools became food for another fungus and grew a cap of white hair:

And I thought no fungus post would be complete without a photo of Fly Agaric, the archetypal fairy toadstool, which is quite plentiful locally.

The toadstools are actually the fruits of the fungus and are grown to distribute its spores.  The rest of the plant is beneath the ground as a network of threads. 

The bright red colour of many fruits seems particularly attractive to birds and in October the migrating Fieldfares and Redwings will strip the Rowan of its berries.

Rowan

Nothing seems to eat the red rosehips though.

Rosehips

Honeysuckle berries

Some of last year's leeks have been left to flower and are providing food for several bees and flies.

Finally, it always seems like autumn when the conkers appear on the Horse Chestnut.

There aren't many Horse Chestnut trees locally.  This one is on Glen Road, Newtonmore.