When looking at the lovely photos Lorna took of the Whitworth Park bioblitz, I spotted that she’d caught something rather interesting in her pictures of horse chestnut leaves. When pictured against the light you can clearly see dark blobs surrounded by paler leaf tissue.
This damage is caused by the horse chestnut leaf miner (Cameraria ohridella). The larvae of this moth live between the upper and lower surface of the leaf eating to create a mine which appears as the paler leaf tissue. These larvae then pupate inside the leaf before emerging as tiny moths. In these photos of the leaves in Whitworth Park, the pupae are at the centre of the darkest spot in the mine.
After spotting these mines, I went back to the park to collect some leaves to show at the Museum’s ‘Nature Discovery’ Big Saturday and found huge swarms of these little moths all over the lower branches of the tree. Hopefully we will manage to collect some to add to the Museum’s entomology collection to match the damaged leaves that I’m preparing to add into the herbarium collection.
This moth was originally discovered in Macedonia, and has worked it’s way across Europe (probably with help from people and their cars). It arrived in the UK in 2002 when it was first spotted causing damage to trees on Wimbedon Common. Ten years later and the moth seems to be thriving in Manchester too. I’m going to add our sighting of the infested tree in Whitworth Park to the data for the Conker Tree Science – Alien Moth Survey Mission. If you have a horse chestnut tree growing near you, you can add your tree to the survey too – whether or not the moths have managed to find it.
I pledged to enjoy the seasons changing by going for a walk every month as part of 2010:International Year of Biodiversity.
Benlech, Anglesey. Easter weekend. Spent most of the time in the wood behind the caravan site making elf houses.
This one has a path and a bench
A front door made of ivy leaves
Daisy and gorse flower garden
The bluebells are here!
Pinus wallichiana (Pinaceae), Bhutan Pine 165/026
This one’s named after Dr. Nathaniel Wallich (1786-1854), who was born in Copenhagen but who spent much of his life exploring the botany of northern India and nearby areas. Wallich was among the most prominent botanists of his times. He introduced the seeds of this pine into England in 1827. The tree is native to the Himalaya, Karakoram and Hindu Kush mountains, from eastern Afghanistan east across northern Pakistan and India to Yunnan in southwest China. It grows in mountain valleys at altitudes of 1800-4300m (but rarely as low as 1200m), and reaches from 30-50m in height. It likes a temperate climate with dry winters and wet summers.
Our three photographs of living trees are of specimens in Sackville Gardens in the city centre and one in a churchyard in Chorlton, Manchester.
Specimen sheet from the Grindon Herbarium
Pinus aristata (Pinaceae), Bristlecone (Rocky Mountain) Pine 165/026
Aristata means bristle-tip, referring to the cone segments. The genus contains three species, including the Great Basin Bristlecone Pine, Pinus longaeva, which is thought to be the oldest living tree in North America. A ring count from a core sample gives an age of 4,700 years. The third species is Pinus balfouriana, or Foxtail Pine. All three are rare, and grow in the mountains of California, Nevada, Arizona, Utah and other western states. It was introduced here in 1863; the oldest known dated British tree is at Kew. It was planted in 1908 and in 1972 was 20’ x 1’-7”. Our three photographs are of a specimen aristata in Wythenshawe Park, Manchester.
“It differs most conspicuously from the two other bristlecone pine species in that the needles usually have only one, (only rarely two) resin canals, and these are commonly interrupted and broken, leading to highly characteristic small white resin flecks appearing on the needles. This feature, which looks a bit like dandruff on the needles, is diagnostic of Pinus aristata; no other pine shows it.” –Wikipedia
Unfortunately, my digital camera can’t cope very well with chiaroscuro contrasts, but I can assure you the white flecks are copiously present on the Wythenshawe Park tree’s needles.
Grindon Herbarium sheet with history of discovery of P. aristata
So here is the last of my botanical, Valentine’s Day posts. I admit this last post is a bit tenuous and I do hope you will pardon my pun.
Looking back over the Valentine’s posts I’ve realised I’ve perhaps not altogether gotten into the spirit of Valentine’s Day with all my talk of wars, slavery and exploitation and I’m afraid with such a tenuous link I will be unable to remedy that now.
This springy quality of yews meant that they were in great demand until bows were eventually replaced with guns. Unfortunately, yew is also a very knotty wood resulting in a lot of wastage, consequently the demand for bowstaves led to the demise of the great Yew forests of Western Europe. Here at the Manchester Museum our archery collection consists of over 4,000 objects.
Yews that manage to avoid the chop have the potential to live for a very long time. The Fortingall Yew Tree found in the centre of Scotland, is believed to be at the very least 2,000 years old and possibly as old as 5,000 years making it the oldest organism in Britain, and maybe the world!
Please note, Yew trees are NOT sweet, in fact they are quite poisonous!
Unusual Trees to Look Out for (1)
Sciadopitys verticillata (Sciadopityaceae), Umbrella Pine 165/025
Sciadopitys is from two Greek roots, meaning (YES!) ‘umbrella’ and ‘pine’. Verticillata means ‘whorled’. A native tree of Japan, there called Koyamaki, it is said to be rare now.
It was introduced by John Gould Veitch into Britain in 1860. As you might guess from its appearance, it’s not a pine at all. It’s the sole member of the family Sciadopityaceae, and is a living fossil, having been present in the fossil record for 230 million years – the first known examples appearing in the Triassic period. At one time it was more widespread; fossils have been found in northern Europe. Research using infrared microspectroscopy has revealed that some of its close family members among the Sciadopityaceae are the source of Baltic amber. (It used to be thought that the amber was from members of the Araucariaceae and Pinaceae families.)
It has no close relatives, although it was formerly classified as a member of the family Taxodiaceae. (Demonstrating these matters of classification to be even more fluid, recent research has shown the Taxodiaceae to be part of the Cupressaceae family, which includes the cypresses, redwoods, cryptomerias, cedars and others. Even the usually authoritative International Plant Names Index still shows the tree as being in the Taxodiaceae.)
Our first two photographs are of a specimen tree in Wythenshawe Park, Manchester. I’ve also spotted a young tree, not much over a meter high, in the botanical woodlands at Portmeirion.
Portmeirion woodlands, 2009
Mature cone, New York Botanical Garden
Sheet from our Grindon Herbarium with illustrations from Louis van Houtte’s Flore des serres et des jardins de l’Europe and articles from The Gardener’s Chronicle and elsewhere.
As part of the Manchester Museum’s Charles Darwin: Evolution of a Scientist programme of events, all the staff in the herbarium were recently trained to take museum objects connected with Charles Darwin out to community groups. During the training we were discussing what it meant to be a scientist, and how it was not necessarily about having the all answers but more about asking the right questions.
I was reminded of that discussion today when, looking at the University of Manchester website, an article about a new tree study caught my eye. The study, being undertaken at the University by Dr Roland Ennos, is looking at why tree branches buckle or split, rather than break cleanly, and how this could help orthopaedic surgeons do a better repair job on children’s broken bones.
What I found particularly interesting is how Dr Ennos came up with the idea for the study. He said: “I was walking through our local wood and breaking twigs off trees and wondering why they were breaking in these two particular ways. I remembered how difficult it was to break branches for firewood as a cub scout – you can’t break fresh branches, you need to find dead wood.”
It’s all about the questions!
Finally, here’s Dr Ennos singing the praises of trees:
“…wood is a marvelous material, the best in the world, better than steel or plastic. It is stiff, strong and tough, all combined, and that’s very rare in a material. Steel is stronger but it’s heavier and both that and plastic take a lot of energy to make, which is important when we are facing climate change.
“We ought to return to an age of wood, in my opinion. We have a feel for wood that goes back to our early ancestors, when we used to cut branches off trees to make into spears and other tools. Understanding precisely how it works should help us design the tools of the future.”
Read the full article here.