Category: Biology

Pasqueflower

Plants are available from garden centres and will grow happily in your garden given the right conditions. These plants belong to the buttercup family and are near relatives of the anemones.

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Image of the day – 150

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

This makes it three in a row for flower images. The pasqueflower (Pulsatilla vulgaris) grows wild in the Cotswolds on dry grassland areas open to full sunshine. It was once quite common, and although not actually threatened, is something of a rarity these days. There’s a Cotwold dry valley site near Cirencester where there’s a reasonably large colony, but to keep the plants safe, the location is not advertised. However, plants are available from garden centres and will grow happily in your garden given the right conditions. These plants belong to the buttercup family and are near relatives of the anemones.

Protecting endangered or rare species (both plants and animals) is of ever growing importance. There are several ways species come under pressure and we’ll look at those first.

Challenges to survival

Habitat loss is the primary cause of decline for many plants, including the pasqueflower. Land improvement, especially the use of fertilisers to increase crop yields, is an issue for plants adapted to poorer soils.

Physical removal of plants or hunting of animals is an issue too. Most species can cope with limited amounts of removal, but if population levels fall drastically, there are real dangers. The dodo died out on the island of Mauritius following hunting by European sailors. The flightless birds were unafraid as they had no natural predators, so they didn’t run away from their hunters. They were welcome fresh meat after weeks at sea on salt beef.

Ecological damage also causes harm, sometimes unexpectedly. After the dodo became extinct, a tree species mysteriously stopped reproducing. Gradually the population was reduced to only older trees. It turned out that the fruit contained toughly seeds with tough shells that would only germinate after passing through the gut of a dodo. Links like this between organisms can be critical.

Climate change is another danger, especially for plants. If climate change is slow organisms can change the range of places where they grow; if it’s fast, animals might adapt, but some plants may need an entire year to move a few metres.

Pollution is a further serious issue and can exacerbate the other problems already mentioned above.

Diseases of both plants and animals can become pandemic and risk extinction, especially when populations are already stressed by droughts, loss of habitat, or pollution.

Attitudes

Given all of the above, what should our attitude be to the current situation?

Some people will shrug their shoulders. – Perhaps they don’t understand the peril the world faces, or they don’t understand the need to help the natural world recover. Or maybe they just feel there is nothing they can do about it.

Others may understand enough of the science to realise there is a danger, to see that it can be reduced (if not entirely averted), and to take some personal actions to help.

Biologists, ecologists, nature enthusiasts, and climate scientists understand only too well what is happening. Usually, they will be trying to communicate the issues whenever and wherever they can.

Followers of Jesus, and people of other faiths will often understand that we should do all we can to protect this world we live in, and live in ways that will reduce the damage.

All of the groups mentioned here are either responding already, or need help to see and understand that the natural world needs our help and that every single one of us can make a difference. Education and commitment are the way forward, so please share this post with anyone you know who might be influenced by it.

See also:

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Image of the day – 60
My Father is a farmer

The heart of a tulip

I worked as a professional botanist when I was in my twenties and thirties, studying and publishing scientific papers on pollen and pollination.

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Image of the day – 149

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

I have another flower image for you today. This one shows the centre of a tulip flower in more detail than you might normally see. I’ve placed the centre of the flower towards the lower right of the frame so you can see more of the petals towards the upper left. You’ll notice that the petals are yellow near the centre, orange a bit further out, and pink further out again. What a beautiful combination!

The reproductive parts

Tulips are monoecious, a botanical term that means each plant produces both male and female reproductive tissues. The female part of a tulip flower has three stigmas in the centre. Unlike animals and some more primitive plants, the male reproduction process doesn’t involve motile sperm. Instead, pollen is released as a yellow dust, sometimes dry and carried by the wind but in the case of tulips and many other plants, sticky and carried by flying insects.

Flowers work as attractive beacons for pollinating insects, they’re usually brightly coloured, are often fragrant which helps insects detect them from a distance, and provide food – sugary nectar at the base of the petals, and pollen. Bees collect the pollen and carry it back to the hive as a protein rich food for their larvae. Plants produce more pollen than necessary and can spare some in return for the pollen transport provided by the bees. The pollen grains stick to the pollinating insects and as they visit flower after flower, some of the pollen is transferred from the anthers of one plant to the stigmas of another. This cross-pollination is exactly what the plant needs for the female tissues to develop further and produce viable seeds.

Tulips have five of these anthers, and if you enlarge the image and peer closely you can see yellow dust clinging to them. That dust is the pollen.

Intricate

It’s an astonishingly intricate process in which the plants depend on the insects and the insects depend on the plants. I could go into much greater detail; I worked as a professional botanist when I was in my twenties and thirties, studying and publishing scientific papers on pollen and pollination. Maybe some time I’ll write a bit more about that.

Next time you see tulips in the park, at a florist or supermarket, or in your garden – just think about the intricate interactions going on right there!

See also:

  • Pollen – Wikipedia (contains a more detailed photo of a tulip anther with pollen, about ¼ of the way down the article. Hint: compare the Wikipedia photo with mine.)

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If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

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Image of the day – 93
Meadow cranesbill
Large White

An old survivor

Much of the old tree would have survived for while, so the new shoot was shaded and would have grown out at an angle, attracted towards the light. Since then, the new growth has itself become a mature tree.

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Image of the day – 138

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every day or so.

Click to enlarge

I spotted this old tree when we visited Blenheim Palace today. It’s probably an ancient oak though I didn’t get close enough to check with certainty.

The thickest part, the lumpy-looking base is the remaining stump, all that remains of the original tree that would have grown from an acorn many hundreds of years ago. That tree was a sapling, then a youthful, vigorously growing tree; eventually if became a mature, majestic oak. But then the rot would have set in – literally. Holes made by a woodpecker, or damage from a storm cracking off a branch, gave access to unprotected wood beneath the bark. Insects may have burrowed into the wood, and eventually fungal spores would have germinated and started the decay process in earnest.

The weakened tree would have lost its vigour and been reduced to a hollow stump and failing branches. But finally, a new shoot must have appeared near the base and formed new, young growth. Much of the old tree would have survived for while, so the new shoot was shaded and would have grown out at an angle, attracted towards the light. Since then, the new growth has itself become a mature tree.

Another possibility is that a branch of the original tree survived, and with the other branches missing, grew into the shape we now see. A careful examination of the tree might reveal the truth. But however this curious old tree survived, it certainly has an unusual story to tell!

Donna and I enjoyed our day at Blenheim and will visit again from time to time this year as the seasons roll by. I’ll probably write about the place again.

See also:

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If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

Image of the day – 27

In the natural way of things, each Aloe will produce an average of one new plant, and the population will remain in balance.

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What’s in an image? Sometimes quite a lot, more than meets the eye.

I’m posting an image every day (or as often as I can). A photo, an image from the internet, a diagram or a map. Whatever takes my fancy.

Aloe aristata

Today’s picture is a close up of an Aloe aristata plant with a developing flower bud. All plants, animals, fungi, bacteria and even viruses have ways of reproducing themselves. That’s one of the defining characters of life of any kind. We can be absolutely confident that the same will be true of any life forms anywhere in the universe.

The Aloe flower bud will develop on a tall stalk and if the flowers that form are pollinated they will produce and release seeds that stand a chance of germinating and growing into new, similar, Aloe plants. In the natural way of things, each Aloe will produce an average of one new plant, and the population will remain in balance.

The only choices available to life are to survive for ever with no reproduction, or to live for a limited time and leave behind new versions to carry on the process. What life cannot do is live forever and reproduce: that would lead to overpopulation and catastrophic failure of resources. Even with reduced family sizes, the planet is no longer capable of supporting the billions of people on our planet. We face catastrophic population collapse due to lack of resources at some point unless we can reduce our population size in some other way first. That’s a matter of simple arithmetic, not a political statement or some kind of guesswork. If we don’t face and fix the issue, something else will sooner or later.

Themed image collections

The links below will take you to the first post in each collection

Cirencester, Favourites, Irish holiday 2024, Roman villa

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If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

Image of the day – 23

By cooperation and coordination they manage all the behaviours and activities that we see on the larger scale. 

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What’s in an image? Sometimes quite a lot, more than meets the eye.

I’m posting an image every day (or as often as I can). A photo, an image from the internet, a diagram or a map. Whatever takes my fancy.

The fresh green of spring

There are few things as amazing as life. Perhaps there’s literally nothing as amazing as life in the entire universe! The photo shows the young, expanding leaves of a small-leaved lime tree (Tilia cordata).

Like all deciduous, temperate trees, leaf buds are formed the previous summer and over-winter after the old, mature leaves fall in late autumn. As temperatures increase in springtime, these buds swell and grow and the young leaves appear and expand. At first they’re a beautiful, pale green (lime green) but become a darker and duller shade as the days lengthen and they mature.

These processes all take place naturally in ways that are more complex than most of us might expect. Both plants and animal bodies are composed of countless tiny cells in much the same way that a large building might be made of bricks. Each cell is alive, contains a full copy of the organism’s DNA, and many of them have specialised roles to play. By cooperation and coordination they manage all the behaviours and activities that we see on the larger scale. So in some respects an expanding leaf is a lot like a growing community of people working together as a village or business. Having specialists makes it possible to do so much more, but cooperation becomes essential, not merely optional.

The rioting we’ve seen in some British cities in recent days has been disruptive and damaging to society as a whole. When the cells of an organism behave in uncoordinated and uncontrolled ways we call it a cancer. Rioting is a kind of cancer in a human society. We all know what happens when cancer becomes so widespread that the organism can no longer function. But organisms have ways of dealing with errant cells before they become overwhelming, and so do societies. Both police action and peaceful counter-demonstrations have been effective in controlling the UK riots in recent days.

Themed image collections

The links below will take you to the first post in each collection

Cirencester, Favourites, Irish holiday 2024, Roman villa

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Useful? Interesting?

If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!