Sunday, August 28, 2016

Bad taxonomy can kill world records

Or, When the world's tallest dandelion isn't a dandelion. 
The motto of The Guinness World Records is OFFICIALLY AMAZING.  And that it is, officially amazing, but not only in the sense that they might think.  When I was a kid in Sweden I loved their orange-colored book, (1975 edition, maybe?) and I read everything in it, and stared at the photos of the man with the longest nails (how did he eat?) and the largest cat, amused and entertained and informed.  Now I get to come back to this memorable source of trivia, but this time for a botanical and work-related reason.

The world record for the tallest dandelion is nearly a foot taller than most people was found by two Canadians 2011.  They had their dandelion verified by two experts in Canada (see below) and accepted by the Guinness office as an official world record. From the Guinness website:
"The tallest dandelion measured 177.8 cm (70 in) and was found by Jo Riding and Joey Fusco (both Canada) in Ontario, Canada. The dandelion was measured on 12 September 2011. The dandelion was found on 4 August 2011 and was unofficially measured at 76 in. The dandelion was then officially measured by NutriLawn and The Weed Man on 12 September 2011 when it had dried out and was measured as 70 in."  (link)
There is no photo of the plant on the record website, unfortunately, but there is a youtube video uploaded by JO Riding, telling the whole story of finding and measuring of the plant. 

By the time the plant was measured it had been dried for weeks, but you can clearly see in the video that it had many leaves on its stem, and that there were several flowers on the top of several branches.  There is no clear taproot and no rosette of basal leaves. To conclude, this was no dandelion. (And just to confirm, the Canadian botanist Luc Brouillet who wrote the Flora of North America treatment for dandelions, agrees with this conclusion.  And he should know.)

There are many species related to dandelions (genus Taraxacum) that are similar to dandelions in having yellow flower heads and 'puffball' seed heads that eventually blow in the wind, but they are not dandelions, they below to other genera.  All of these are members of the sunflower family (scientific name Asteraceae), and dandelion and its relatives are members of the Cichorieae (aka Lactuceae) subgroup (=tribe) that has members with milky sap (latex) that you can see if you break a leaf or stem.
Dandelion (Taraxacum)  from Lindman's Bilder ur Nordens flora, Public Domain.
Here is a real dandelion, a species in the genus Taraxacum. All the leaves are in a basal rosette at the base, and from the middle of the rosette a light-colored, hollow stem comes up and holds just one flower head. There is a big taproot under the plant that can survive year to year, and that is why they are so hard to get rid of - you have to dig them out. It is a perennial problem - cut the flower head stalk off with your lawn mower and it just sends up a new one from its low stem and perennial root.
Milk Thistle (Sonchus arvensis), illustration from
Otto Wilhelm Thomé Flora von Deutschland, Österreich und der Schweiz (1885), Public Domain.
And here is a weedy look-alike, but check out the differences in the position of the leaves and the branched stems with many flowers.  This is a milk thistle (Sonchus), which is probably what was reported from Ottawa as the world's tallest dandelion. It is unclear if the two Ottawa companies that certified its height, Nutri-Lawn and Weed Man, also certified its species identity, but both companies should be very familiar with dandelions and other weedy species.  Nutri-Lawn is a lawn care company specializing in "ecology friendly lawn care" and Weed Man, another gardening company has a very funny green man as their home page mascot.  It might be that Guinness World Records didn't ask for species verification. 

And then there was this UK news story this summer, Man accidentally grows the 'world's tallest dandelion plant'
Screenshot from The Telegraph (UK) website (link) by, 18 Aug 2016. Fair use.
" Mr Daniels is keen to get his dandelion officially measured as soon as possible before it starts to wilt or dry out. He added: "I'm not a gardener hence why I'm growing a dandelion, it is just luck that it has grown so big as I have done nothing to it over then let it grow." A Guinness World Records spokesman said: "We invite the claimant to make an application via our website in order for us to be able to ratify the achievement."
This is not a dandelion either. All those little flower heads in a strongly branched inflorescence and the leafy stems with bluish-green leaves with light-colored mid veins indicate that this seems to be Lactuca, maybe prickly lettuce (Lactuca serriola). Lactuca is the same genus as your supermarket lettuce, but this is a wild species. This is how Lactuca looks like. Some species have blue petals, other yellow.
Wild lettuce or prickly lettuce  (Lactuca serriola) from Köhler's Medizinal-Pflanzen, Public Domain.
For the record, WeedZilla with a height of 12 feet isn't the World's tallest dandelion either, that is something else in the sunflower family. It is a giant weed indeed, but not a dandelion. Sorry.   

The strange thing is that dandelions are not hard to identify with certainty if you know what to look for.  The book Foraging & Feasting: A Field Guide and Wild Food Cookbook by Dina Falconi includes a great 'plant map' illustrated by Wendy Hollender of all the good key characters for dandelions. You can also read about dandelion's great benefits and ancient ethnobotanical uses.  

I am not writing this to point out that people identify plants wrong.  That happens all the time, and is just a matter of education, curiosity, and interest in plants that live around us.  There are plant identification forums online with over 50 000 members, and the fact that people are curious about strange, cool, and giant plants is a great thing.  People should ask about plants, and let themselves be amazed by them. It is OK to know little, especially if you want to know more and satisfy your curiosity.

The problem is the fact checkers at Guinness World Records who put themselves and their company into this embarrassing situation.  First, they should make sure they actually have the right species in hand. The easiest for this is to have photos of the plant while alive, you know 'pics or it didn't happen!'.  They should also require a pressed specimen of the plant, not just air dried, but pressed between newspaper sheets so it is preserved and flat.  That way specialists can look at it later and say: "yep, you have a true dandelion!", or "sorry, that is a milk thistle, nice plant anyway!"  This is called vouchering and is standard practice for all species reports, including DNA testing, species inventories, herbal plant identification, and chemical analysis.  There is no reason why Guinness World Records could not implement this, and have a botanist verify the species identification and have a link to an actual preserved specimen (the proof). 

So, what is truly the record for world's tallest dandelion? Well, there are reports out there that show real dandelion (Taraxacum species). So far, the record seems to be the dandelion found by a Norwegian boy, Bjørn Magne, with a 108 cm (42 inches) long flower stalk, and reported to World Record Academy in 2007.  Before then, the Guinness World Book of Records had a 39-inch tall Swedish dandelion from 2003 as a record holder. The Nordic countries seem to be great for further giant dandelion exploration.  To inspire you, here are some dandelions on Iceland's lava-covered plains in the never-setting sun of Nordic summers. 
Dandelions on Iceland. Photo and copyright by Didrik Vanhoenacker (thanks for letting me borrow the photo).
PS.  Thanks to Asteraceae specialist Torbjörn Tyler, field biologist-on-call Didrik Vanhoenacker, professor emeritus Arthur Tucker, and dandelion taxonomist Luc Brouillet, who all helped and gave feedback on research for this blog post.

Thursday, August 18, 2016

Lichen or Moss - that is the hard question... also for science editors

It appears that New Scientist needs to rename their recent story " Without oxygen from ancient moss you wouldn’t be alive today" to something more like "Without oxygen from lichens you wouldn’t be alive today", based on their featured image. The story was posted on their website on a few days ago, and features new research findings of how the earliest land plants (bryophytes/mosses) helped put oxygen in the atmosphere; here is the webpage: 
Screenshot from New Scientist website (link) by, 18 Aug 2016. Fair use.
The story is based on a very interesting paper in PNAS by Timothy Lenton and colleagues at Exeter University.  A science writer probably wrote up the text, but along came a photo editor, who went to a stockphoto gallery, in this case Getty images, to find a suitable image.  And he/she selected a lichen, not a moss, since that 'moss' is what the photographer had written in the description. Nobody appears to have checked with the authors of the paper or any other botanists if the image was suitable or correct.  (My advice for scientists is to always provide your own images for news stories, for exactly this reason.)
Screenshot from Getty Images by on 18 August 2016 of 
'Close-Up of Moss on Rocks' photo (link), featuring a lichen, not a moss. Fair use.
The bushy, light-colored lichens of the genus Cladonia shown above (also known as reindeer lichens and many other names) are seemingly perpetually misidentified and mislabeled as mosses, I have written about this elsewhere here on the blog.
White lichens, green mosses, and Swedish Christmas...
Reindeer moss is a lichen, not a moss

So how to avoid mistakes like this? It would be very helpful if stock photo companies demanded accurate descriptions of photos, and if media checked the images with the people that know, not the least the authors of the paper that is featured.  I can just imagine their frustration and possible horror to have their bryophyte story illustrated with a photo of a lichen, especially since there are so many gorgeous moss photos.  

PS.  Thanks to TT who notified me of this mistake, which hopefully will be corrected by the New Scientist editors very soon.
PS2. UPDATE: The photo is now corrected in the article in New Scientist.