Vegging Out. Part 3.

More on vegetative plant identification. A useful stumbling block…

Attempt #3. Great Willowherb.

Keying out a dandelion and petty spurge using The Vegetative Key to the British Flora been reassuringly straight forward. I was feeling confident (cocky), so when I saw this growing in a wet ditch while out on a job I thought I’d have a bash at it…

#GreatWillowherb

That picture doesn’t show it very well but it was growing out of a water body. I had it in my mind that it was therefore going to be an aquatic plant. I don’t know my aquatic macrophytes very well so for all I knew it could be a young bog bean, marsh marigold etc.

The key took me through the following features (my descriptions below are not always direct quotes from the key):

  • Leaves simple
  • Leaf margin toothed
  • Leaves alternate. This took me to KEY N
  • It’s a herb
  • Stipules absent
  • Latex absent
  • Leaves with hairs all simple or hairless
  • Leaves with pinnate or palmate veins
  • Petiole developing 1-2 hollows (Ranunculaceae) Key RAN. So now I’m thinking maybe it will be marsh marigold though if I’d looked at a photo I’d have realised straight away I was wrong, the leaves are totally different.
  • Leaves lanc to ovate, not orb, unlobed but weakly toothed.

Here is where I knew I’d gone wrong. I spent some time trying to convince myself that that the leaves could be described as lanceolate to ovate but they just aren’t! They are obovate if anything. I was seduced by the weakly toothed bit making it hard to let it go. You brain likes to latch on to a bit that works in a plant description making you blind to all the other bits that don’t.

So there’s lesson one: Don’t ignore the descriptive elements you don’t like. If it’s wrong it’s wrong.

Next it all kinda fell apart as these things sometimes do when you get stuck. I misread an early line of text and convinced myself I should have answered yes to:

  • Plant with submerged or floating leaves. Key E

Lesson two: Always read the key carefully and make sure you’ve understood it before moving on.

I started again and after a while trying and failing I admitted defeat and asked Miranda what it was. She took one look at it and said: “It’s great willowherb”. My heart sank. Oh yeah, I thought. “But it was growing in water” I said. “Yeah it often does” she said. “Oh”. I set about reverse engineering the key so I could see the route I should have taken.

#VegetativeID

It seemed to me that I would have needed a stem to use The Vegetative Key. I had another go using a young willowherb growing in my garden and again became stuck without a stem…

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I consulted my favorite social media resources to check I was right. The BSBI on Twitter, and the ever obliging folk of Facebook’s Wild Flowers of Britain and Ireland group confirmed my suspicions. I asked Sarah whether she had any advice on getting further than ‘willowherb sp’ with plants this size. Her advice was: “I’d walk on by…willow herbs are a really tough group, they also hybridise, and doing them vegetatively is tough enough without doing rosettes.”

Lesson three: You need a stem to identify willowherbs using The Vegetative Key.

The next day I was working in North Wales. I’d been rummaging around in some woods and was on my way back to the van, parked in a lay-by on a country road. I looked into the roadside ditch as I walked along and saw lots of young great willowherb (Epilobium palustre) growing there…

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Lesson four: Mistakes and failures can be every bit as useful as simple successes. 

It took more than the key on its own to get there but knowing a species at every stage of it growth is so useful.

Thanks for reading. I hope you’ve found it useful or at least reassuring. Onward and upwards! More to follow…