
Thursday, 29 September 2022
The Holly and ...

Saturday, 16 December 2023
The point of Holly
I wrote a fair amount about Holly last year (see here) so you can follow that link to read more about the plant and the lore surrounding it. Holly is a native tree to the UK and was a sacred trees to our ancestors.
I thought I knew a lot about Holly. However, a recent post on social media by a group that celebrates trees stated that:
Holly leaves are naturally leathery and have an oval, smooth edge. However, when the plant gets predated by deer or cattle, it switches genes on to make them spiky when they regrow. So on taller Holly trees, the upper leaves (which are out of reach) have smooth edges, while the lower leaves are prickly.
It was accompanied by this photo:
Was this true I wondered? If so, I was unaware of it. And, besides, the term 'switches genes' didn't really make a lot of sense to me. So I did some research and asked a few questions.
The first few responses I got back were from gardeners - both professional and amateur - who assured me that the same effect is created by pruning. As one wrote: 'Pruning is just intentionally doing what nature does by accident. Want a taller plant? Trick it into thinking critters are nibbling down low. Want it be shorter and fatter? Cut the top so it thinks it ran into something. You trick the plant into taking the shape you want.' But that didn't explain the change in leaf shape.
Another person explained that: 'In South Yorkshire from the 14th to the 18th century, there is documented evidence of Holly being used as fodder for livestock particularly in winter i.e. when snow prevented access to grass. This took advantage of the fact that the upper leaves of Holly are smooth (as they don't need to protect themselves from browsing by deer like the lower leaves). Special plantations of Holly were called Haggs, and is still a lot of modern place name evidence e.g. Hollin, Hagg etc are all linked to this practice - Fox Hagg in Sheffield, Hollin Busk in Deepcar etc.'
This goes some way towards validating the cause (predation) of leaf prickles but still didn't explain how the plant does it. Thankfully a biologist on Reddit then came forward with this explanation (quoting from a paper*): 'All of the leaves on a tree are genetic twins and share exactly the same DNA sequence. By looking in the DNA for traces of a chemical process called methylation, which modifies DNA but doesn't alter the organism's genetic sequence, the team could determine whether leaf variation was a response to environmental or genetic changes. They found a relationship between recent browsing by animals, the growth of prickly leaves, and methylation. "In holly, what we found is that the DNA of prickly leaves was significantly less methylated than prickless leaves, and from this we inferred that methylation changes are ultimately responsible for leaf shape changes," Herrera said. "The novelty of our study is that we show that these well-known changes in leaf type are associated with differences in DNA methylation patterns, that is, epigenetic changes that do not depend on variation in the sequence of DNA."'
So, now we know. It is apparently true that predation of Holly causes lower branch leaves to get spiky. And not just by deer and cattle. There are other nibblers too such as caterpillars and weevils. And many birds and even foxes eat the berries so may damage the leaves that way.
But it is another fascinating example of cooperation in the natural world - the leaves are predated and get spiky - this provides birds and small mammals with a protected space in which to nest - they eat the berries and then distribute the seeds in their droppings - more Holly trees grow to feed the deer and other leaf eaters.
I love those kinds of stories. We're starting to understand that nature isn't all 'survival of the fittest' after all. Firstly, that was a misquote as Darwin actually said 'Survival of the most fit' i.e the best suited to its environment. And, secondly, species that cooperate tend to do better than species that don't (for a great example of this see here).
That applies to humans too. No one person can build an Airbus A380 but thousands of humans working together can. Cooperative behaviour is what made the human race the dominant species on this planet.
Now we need to learn to cooperate with other species so that we all flourish.
___________________________________________
*Herrera. C, Bazaga. P, ‘Epigenetic correlates of plant phenotypic plasticity: DNA methylation differs between prickly and nonprickly leaves in heterophyllous Ilex aquifolium (Aquifoliaceae) trees’, Botanical Journal of the Linnean Society, Wiley, December 2012, DOI: 10.1111/boj.12006
See also this article published by the Royal Linnean Society (Royal Society for Animal Biology).
Thursday, 29 September 2022
... and the Ivy
Ivy, like Holly, is an important evergreen edible plant species in UK woodland. It's one of only five woody climbers and, like Mistletoe, it can form dense growths in canopies that can cause harm to the host.
There are many different species of Ivy - English Ivy, Glacier, Swedish, Needlepoint, Boston, Algerian, Irish, Himalayan., Poison, and more - and they vary in colour from near white through variegated forms to deep glossy green. The leaf shape can also be anything from spear shaped to three lobed to five lobed depending on maturity and where on the plant the leaf is.
Even common English Ivy (Hedera helix) can have a number of variant shapes and colours. Here are a few I photographed in the wild yesterday lunchtime:
They have two leaf types: lobed juvenile leaves are found on creeping and climbing stems; and unlobed adult leaves grow on fertile flowering stems exposed to full sun. The juvenile and adult shoots also differ. The former are slender, flexible and have small roots that anchor the shoot to rocks or tree bark. The latter are thicker, self-supporting, and don't have roots.
Tuesday, 30 May 2023
End of May ramblings
Wednesday, 30 November 2022
Leaf of the Day - Day 30
On the final day of November, and with Christmas rapidly approaching, the Holly, the Ivy and the Mistletoe are bursting with berries. It seemed appropriate to give them a platform today.
And I thought I'd include this little oddity too - a variegated Holly leaf with only one spike, bless it.
Thursday, 21 July 2022
Rowan tree, red thread
Hold the witches all in dread.
It's possible you might just recognise those lines as the chorus of a song by Steelye Span called The Twelve Witches. The song is based on a traditional counting tune (like Ten Green Bottles or Ten Little Indians) but catalogues the particular powers of a coven of twelve witches.
The chorus then describes a traditional form protection against them - making a cross from rowan twigs, wrapping it in red thread and hanging it over the door.The emphasis on the colour red and the wood of the rowan itself perhaps comes from the fact that these trees, with their distinctive red berries, had long been associated with agriculture. Trees like the rowan – along with holly, elder and hawthorn – all came to be a common feature in the landscape due to the process of clearing the land for cultivation. It’s notable that all of these trees bear red fruits except the elder, although it does produce a dark purple berry that gives up a red juice.
Top to bottom: Elder, Holly, Hawthorn (haws), and Rowan Berries.
There are many rites and rituals in paganism that involve the rowan, mostly centred around the time of Beltane (May Day). If you want to read a lot more on the subject, click here.
Rowan berries are edible although, as you'll know if you've ever tried eating one off the tree, they are very bitter and astringent - think cranberries turned up to 11. Or 111. However, that doesn't seem to worry the birds who will soon strip a tree clean. Which is a real shame because the berries, if given an extended period of cold weather and several hard frosts, eventually become quite palatable. However, you can still use them as an ingredient in hedgerow jams and jellies by pairing them with super sweet fruits like blackberries, strawberries and damsons. Using a limited amount just takes the edge off the sweetness, which makes it a nice accompaniment for strong meats like venison or lamb. The Vikings certainly rated them very highly and surviving recipes show that they ate them with game.
Or do what I do and make a rowan berry schnapps. I got the recipe from the Forager Chef blog and it's simplicity itself. In preparation, gather in a good pile of ripe berries and keep them in the freezer for a month or so.
Then you get a half litre of vodka - a cheap one will do - and mix in half a pound of sugar and a good handful (10pz) of rowanberries. Put the mix into sealed bottes or jars and leave for a couple of months. Then strain through muslin and drink.
As the site says, 'The maceration seems to draw out the flavor of the rowanberries, without the bitter, tannic quality. The colour is a beautifully pale orange that reminded me a bit of rosewater. The fruity taste of the berries, typically obscured by bitterness, comes through in the finished product, and there’s noticeable aromas of grapefruit and orange peel.'
Definitely worth a try and a nice alternative to sloe gin at Christmas.



.jpg)














































