Sunday 29 March 2020

The Dandelion ID bug: Tim says it’s contagious…

Tim in his garden with some dandelions
Image courtesy of T. Rich
Recently I’ve been noticing people posting photos of dandelions in their gardens on social media and expressing surprise that there are almost 250 species in Britain and Ireland! A few brave souls have been trying to put them into sections (there are eight sections) and a few have even tried to ID them to species – no easy task – so I thought we needed some help. 

Who better to advise us than expert botanist Tim Rich, co-editor of the celebrated Plant Crib and author of numerous BSBI Handbooks and scientific papers published in journals such as British & Irish Botany and its predecessor New Journal of Botany.

Over to Tim: 

“Stuck at home? Frustrated? Alone? Anxious with all the uncertainty? Well that’s what happens when you try to identify dandelions in your garden; it’s another contagious bug.

“Start by diagnosing to section, which you should be able to pick up quite quickly as most species in the garden will be section Ruderalia with some Hamata, and occasionally one or two Erythrosperma or Celtica. Generalising, Ruderalia will be in lawns, flower beds, paths etc. - only species with prostrate leaves survive in lawns due to mowing, conversely those with upright leaves grow in wild parts where they can compete with other vegetation. Dandelions in section Hamata tend to be a bit weedy in ecology so like scruffy flower beds. Those in section Erythrosperma prefer dry open conditions such as gravelly drives and path edges. Those in section Celtica like rockeries and patios, perhaps mimicking their natural habitats.

“Diagnosing to species is much harder. I’ve recorded 8-12 species in my three recent gardens, excluding those escaping from my pots (the neighbours have been socially distancing for years).

So here are a few golden or rather yellow rules:
  • Use the right reference sources; the Plant Crib Taraxacum accounts are the primary sources coupled with the BSBI Handbook, Dandelions of Great Britain and Ireland, subject to updates in the Cribs. Stace's New Flora of the British Isles 4th ed. has much the same key to sections as the BSBI Handbook, but the illustrations are too diagrammatic for me.  
  • Be cautious of online picture sources: all of my pictures on iSpot or Dandelions of Cardiff have been verified by the BSBI Dandelion referee so are reliable [Ed.: access to BSBI’s network of expert referees for difficult plants is one of the benefits of membership].    
  • Learn what NOT to try to identify – such as plants trampled on paths, those in regularly mown lawns (even if not yet mown this year), plants regrowing after being weeded, plants in shade, those with feeding damage (keep that tortoise off) or anything that looks like it has a virus or a cough. That makes the job smaller - doesn’t leave a lot in my garden!
  • Select good healthy material with range of leaves, mature buds and open flowers (bract characters are taken from mature buds just before they open). Seeds can be obtained by clocking an immature fruiting head on the windowsill (as above).  
  • In lowland gardens there is only a narrow window for identification/collecting in March to April. Don’t bother outside this period as summer leaves are atypical, though as you sunbathe on the lawn you can impress your friends with "That’s Taraxacum multicolorans you know!”.
  • It is usually very hard to identify dandelions reliably from photos alone, so confirmation will be needed from well-collected and quickly-dried specimens (see guidance in the Plant Crib and the BSBI Handbook on Dandelions). If you need an excuse just to look, the bees and hoverflies will be grateful. 

“The three PowerPoints I presented at the BSBI Recorders Conference in 2018 provide more detailed help for those getting started:

“And when you’ve caught the dandelion identification bug, unless carefully isolated, next year you’ll find they will have infected your whole garden and life. There is no cure”.

Many thanks to Tim for introducing us to the dandelion identification bug and providing the images on this page. If Tim’s suggestions have prompted you to have a go at identifying dandelions to section or beyond: good luck, let us know how you get on! If you’ve decided that you’d rather just call them all dandelions and focus on identifying some less challenging plants, check out Tim’s helpful series of botanical ID videos via the links on this page. 


  1. They are tough plants.
    I have found dried out roots trying to set seed and even one that was still growing with its taproot impaled by a couch grass root.
    I have posted photos on I-spot.

  2. LOVELY Tim (Louise). Thanks
    Anonymous' link above brought me here. Quite a few people are posting in iSpot I suspect Hot links are not allowed here (copy/paste) Everyone is welcome in there. We are keen to gather Observations made within (because of?) the Current Restrictions

  3. Taraxacum is a infectious bug.In these isolated months getting to know Dandelion is a joy.

  4. I have just watched the April 2020 you-tube on Introduction to Dandelions; it concentrate on the Sections. I found it very useful; you may too. I found it through the the BSBI website.
    (copy and paste as hot links not allowed here.)


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