I am told the same happened in the 70s with Dutch elm disease (so media-worthily shortened to DED) caused by fungi of the genus Ophiostoma. A friend was so surprised to see some elm seeds a while ago that she did not immediately identify them as such: she had unconsciously assumed there would not be literally any left...
It is indeed a serious matter when a new pest, disease or invasive species is introduced in a new area. And Chalara is a notifiable disease, so if you spot it anywhere in the UK, you have to report it. What annoys me is the tones, as if it was not our very own fault, the fault of human activity, that is. It often is. In this case, one of the ways into the country for the fungus was likely that we imported trees from foreign nurseries because it was cheaper than growing them here.
There are other famous cases of imported "aliens". For example in the case of Fallopia japonica, or Japanese knotweed, which was highly prized for its garden worthiness in times past - fancy that, we are today introducing, to deal with that problem plant, a pest that is non-native too: insect Aphalara itadori... suspending judgement on that.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_ZX6brtjdzWaFyC2tQPBEd_m-kTkaDqLCQElmSg8V7pzooRZ5oTscUbJUfEPM5gaHaa8-i8aUXfuPIvYeLHwmBzU-QuhKOamltOuIeuVFPa6KzkQRKQxhMSW2O307badls-pw1vYR8cc/s320/9530989386_13093a5a2a_z.jpg)
Scientists across Europe are on alert and mobilised trying to find resistant specimens (there seem to be enough genetic diversity in the wild for that to happen) in order to understand what makes them so... they have also suddenly broken into the 21st century social media world by creating Facebook application "Fraxinus", to harness the power of the crowd in identifying gene sequences...
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Fraxinus excelsior 'Stricta' |
Back at work, today it was team day and we worked on the tree circles in and around our Fraxinus collection, so I had the opportunity to observe some close up.
Fraxinus americana 'Autumn Purple'
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![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHg_W9KQsXLMMVxyOy1f57haJebOFTQd45MYt1YX8WkF6TmCRMEaohApOLmgM6BQtoiWWVNMkq8SgeAK38DbEzkso4N8ZjTCRU47QcBlSeWTTupXIZ-TcDAk2Rrknk_5FDlbNBnNcQmEI/s200/9509068663_bd1112710d.jpg)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjI0tdv3LWZL5Cf9WVxQAaaCY1n7qkbyudiqpXEL5SK7xdT2MBKczwcg8ODWwr4T2loJWsIaaCxL-yZ63bCbirb9qQuwD2bGwqz0D-McoTp02SlPpWemz1bBpM_XyLlwHCv07QYEYIlcgk/s200/9509063463_27e4dc633e_z.jpg)
Fraxinus paxiana
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![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXFEiZ-t1_g_5gS6czTvgF_7A8H35Kwi1EMkA-JAMrwGZml7DAfpoCjy1o-maP6mRDzUf52t3pT9gwsSk9eVDoRf3kk2h5dC-deDujrHMmsfY9tgnfjOq_-bdMrJrvBHKt7LuFZPkEKU8/s200/9511872760_1f142a419b.jpg)
The first thing I noticed is that not all ash has black buds like the F. excelsior species: they are all actually quite different in colour, ranging from pink to orange-brown and to black.
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Fraxinus sieboldiana |
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Fraxinus excelsior |
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Fraxinus mandschurica |
Fraxinus ornus
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![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmbSPOPbH3nci7d1-WqTYb8slWUpd9XnwlifKfHEMN5WG2Gu9PBQxuSS0iZ8yONUVsHA0V1CpFCzrxCko6MA4kX8jLpg1C1h948zchn9PhhHTKrIuVfb2JKI6Zr_OFPbO4nNFIuWH1h5A/s200/9509103579_4122db1c96_z.jpg)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieFKiXkJtKtYq6jP-JUwU1tA9d8P-sqwcD5X2s3H-Wd0BeuTYtkxW6cHdce5dWMWpjYFmp7noYsoFML9c5gRVy745kS2galZdUdlZ27alQruxBz8j9KZ3zl-Egmho9e7_YUQXyAZbR1eA/s200/9511898046_2fe28caf38_c.jpg)
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