Taraxacum, Section Erythrosperma in Kent - April to May 2020
When I started out in botany, I thought there big and small Dandelions, but that was it, they were just Dandelions. Several years on and I now know there are about 250 micro species, which are very difficult to identify. They clone themselves year on year so do not hybridise with other species. As a result, these seperate species have been placed into different sections. The vast majority of species are in Section Ruderalia (now called Taraxacum) and are mostly alien and thus not considered rare.
After the easing of the 2020 lockdown, my partner and I took a walk near Sevenoaks and found an unusual looking Dandelion. I took a specimen and sent it off for an ID and it came back as Taraxacum gelertii, a Section Celtica plant rarely found in Kent. So that fired me up to have a look for them properly in 2021.
The Dandelion year only lasts from April to early May as plants change the shape of their leaves and mis-identifications can occur. As such, I started looking in early April. I initially found a Section Ruderalia at Ranscombe Farm. It was so impressive and large, I thought it must be easy to identify. So I took a flowering head and a leaf and took it home and got the books out. I soon became aware that these plants may have different shaped inner and outer leaves and I was curtly told without them not to bother with an ID. Ignore the identification given on the photo below, that was my first thought and it wasn't confirmed so it is probably wrong!
As such, I gave up on these.
The Section I decided to look for in 2021 was Section Erythrosperma. These are always very small plants with small flowers and very much having heavily cut dissected leaves. The places to find them would be established ancient grasslands such as on chalk scarp slopes, sandy heaths and coastal areas too. If a place gets ploughed it becomes full of Section Ruderalia in no time so I didn't bother looking in field edges.
The biggest issue in chasing Dandelions is in having some voucher specimens that you can refer back to, to compare with. That was the purpose this year, to get some specimens and have them all identified properly by the BSBI Taraxacum referree. Once you have these, you can speed up identification, so next year I should be able to identify a few more than previously.
The other issue I fould was that many venues had zero Dandelions in the whole area of the type I was looking for. Of course, there would be the occasional Section Ruderalia wherever one went, but I was surprised how hard it was to find some specimens to identify.
My first find was a major one. It was on a short turf chalk bank local to me and I had the County Recorder out to verify some Viola hybrids I had found in the same meadow. When I went back the following day to get some better photos, I noticed some quite small Dandelions dotted here and there. I took a sample; lots of photos and lots of notes and sent it off for an ID from the referee.
I was very pleased to find it was determined as Taraxacum parnassicum, a species new to Kent and never recorded here before. Here's a composite photo which includes the notes needed to identify these.
Most referees appreciate you taking the time to try and work out what you have found first. I had keyed this plant out several times and thought it was indeed T. parnassicum, but as it had not been found in Kent before, I doubted my findings. It's nice to get it right from time to time!
My next nice finds were coastal. I visited Sandown, North of Deal town, and walked the path towards Sandwich. There were plenty of small Dandelions here and they all looked the same. They had very heavily dissected and contorted leaves which alone should have told me these were T. dunense, however, I'd never seen them before and real life specimens rarely match what's in a book perfectly.
Here is the habitat for T. dunense.
One of the advantages of pressing a plant is that once pressed you can arrange the specimen more clearly than it was in real life and without distracting (usually green) backgrounds too. If you compare the plant to the photo top left above, you can see how much easier it is to use the herbarium specimen to ID a plant without all the goings on of a background. I also found that once pressed and dried, many flowers would ripen the seeds within a head, thus showing you the achene colour, a useful ID tool for this section of plants.
I include the next specimen as a word of warning. It was a small Dandelion growing on the sea wall with a small flower too. The leaves were completely different to that shown above, so I took a sample.
As you can see, I learned a lesson here! Turned out this was a stunted Section Ruderalia. I've left this in my herbaria as a lesson learned too.
I then tried some inland sites and my local Dartford Heath seemed like a good place to look.
I found several Section Erythrosperma plants on the heath. The first was the only one that I didn't need an expert ID verification for, and that was T. brachyglossum. This is because the rays are only a little bit longer than the bracts so it looks partly closed all the time and the flower is diminuitive. No other species has this character.
The next find was also all over the Heath and I found it in 3 seperate monads. It was T. haworthianum, a first for VC16 West Kent. The only other Kent record was from Hothfield in East Kent from the 1970s, so this was a good find indeed. What I particularly noticed about these plants was that they had bright purple blobs on the tips of the outer bracts (described as "corniculate" below). It was a constant feature and ruled out other similar species, so look for them!
This next plant is perhaps the commonest Section Erythrosperm in Kent, it is T. oxoniense. However, this plant can and does have highly variable leaves, but the trilobate end of each leaf seems to be constant. Another lesson came from this plant and that is that the referee said that some plants can have light brown achenes (seeds). He also mentioned pollen present can just amount to a few grains, so there probably was some pollen present - I just didn't look hard enough! These things are what threw me on this plant as no Section Erythrosperma had this colour seeds and pollen should have been present for it. It goes to show that snippets of experience that the referees hold in their head, don't always make it into the books!
T. oxoniense
I then found more T. oxoniense at Queendown Warren, a KWT reserve, too.
The greens at Littlestone on Sea provided the last plant of note that I found.
Here, I found numerous plants that initially looked the same as T. dunense shown above. However, by now there had been no rain for 4 weeks and the plants were drought stricken so I wasn't sure. The referee stated they were in fact, T. lacistophyllum and this is common at Littlestone and Dungeness where I also found it and one sample at Queendown Warren too.
Look at the leaves above! Drought stricken and described as "crisped" by the referee. I got around this by soaking the specimens in water when I got home thus -
The leaves swelled up nicely and then I pressed them in their correct shape.
Well, that's about it for Taraxacums for 2021. I didn't find anywhere near as many species as I had hoped, but those I did find were encouraging with 2 species not previously recorded in VC16 West Kent, so it was definitely worthwhile. I may do a similar exercise next year, I may not. I know the referee is rushed off his feet identifying Dandelions at this time of the year, so it's best to record the samples and wait until the rush is over before submitting your finds. Only BSBI members can use this service, see BSBI and they have referees for most species of plants.
A fasciated Dandelion from Section Ruderalia (Longfield). Avoid these and any that are mown, trampled, or grazed. That rules out a lot of Dandelions!
I hope you enjoyed the blog - it was a bit technical this time, but it helped to show that botany isn't always about the easy to identify plants. But importantly, it was still FUN looking.
Take care
Dave
Twitter: @Barbus59
Fantastic!
ReplyDeleteShame the dandelion season is so short! Have you tried the local hawkweeds? There are some interesting colonies of Hieracium species in VC 16, and a great BSBI Handbook (#20) to guide you on your way.
Well, I found some T. acistophyllum on th eKent coast on 05/06/21 and it looked just like they did on early May, so perhaps it's a but longer than usual this year. I haven't tried Hieraciums as yet or Rubus fruticosus either! I think Taraxacum could take many years to get to grips with all Sections, especially Ruderalia. I tend to see only 1-2 different hawkweeds each year too, but then I don't go looking for them either! Rgeards Dave
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