Herb Robert v Little Robin

Michael J Davis

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Aug 11, 2015, 12:12:13 PM8/11/15

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Please can any botanists here help?

I took this photo on Sunday:-

https://www.flickr.com/photos/watchman/20400744612/

As the flower was around 1cm dia I assumed it was Little robin (Geranium
purpureum) but as you will see from the discussion - a local friend
started by disagreeing.

Now we are both confused; is Herb robert (Geranium robertianum) able to
have smaller flowers than the 2cm mentioned in my (various) id books?

Thanks for your help!

Mike

--
Michael J Davis
<><

Asha Santon

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Aug 11, 2015, 2:47:36 PM8/11/15

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I cannot tell anything from the photograph unfortunately.
The 20mm is approximate but not to the extent that the two could be
confused. What colour was the pollen, orange or yellow?

This is Herb Robert (orange pollen)
http://nature.opcop.org.uk/flora/63090667.htm

This is Little Robin (yellow pollen)
http://www.brc.ac.uk/plantatlas/index.php?q=plant/geranium-purpureum
(click to enlarge that one)

They are quite different.
Perhaps you can see more on your photograph in its original size than I
can via the link you provided.

--
A S
http://nature.opcop.org.uk
I knew the Triffids were real when I saw the signs
Caution: Heavy plant crossing

Malcolm Ogilvie

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Aug 12, 2015, 2:37:00 AM8/12/15

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Little Robin only grows in SW England, so where did you take the photo?

Malcolm

Michael J Davis

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Aug 13, 2015, 4:13:05 PM8/13/15

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Malcolm Ogilvie <MAOg...@indaal.demon.co.uk> was inspired to say

Rochdale NW England. Another one from our hedgerow:-

https://www.flickr.com/photos/watchman/20521673576/

Bigger photo - Asha's previous post seems to nail it as Robertianum in
spite of the size discrepency.

Thanks

Michael J Davis

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Aug 13, 2015, 4:13:05 PM8/13/15

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Asha Santon <as...@santon.invalid> was inspired to say

>On 11/08/15 17:11, Michael J Davis wrote:
>>
>> Please can any botanists here help?
>>
>> I took this photo on Sunday:-
>>
>> https://www.flickr.com/photos/watchman/20400744612/
>>
>> As the flower was around 1cm dia I assumed it was Little robin (Geranium
>> purpureum) but as you will see from the discussion - a local friend
>> started by disagreeing.
>>
>> Now we are both confused; is Herb robert (Geranium robertianum) able to
>> have smaller flowers than the 2cm mentioned in my (various) id books?
>>
>> Thanks for your help!
>
>I cannot tell anything from the photograph unfortunately.
>The 20mm is approximate but not to the extent that the two could be
>confused. What colour was the pollen, orange or yellow?
>
>This is Herb Robert (orange pollen)
>http://nature.opcop.org.uk/flora/63090667.htm
>
>This is Little Robin (yellow pollen)
>http://www.brc.ac.uk/plantatlas/index.php?q=plant/geranium-purpureum
>(click to enlarge that one)
>
>They are quite different.
>Perhaps you can see more on your photograph in its original size than I
>can via the link you provided.

Thanks - that's really helpful.

I've found another example with the largest flower I can find c.11-12mm
across:
https://www.flickr.com/photos/watchman/20521673576/

Don't be confused by the ruler - that suffers from parallax being some
40% behind the flower.

From your examples it has to be Herb Robert - though we're a bit late
for the pollen, what's there is orange (especially compared with the
Little Robin examples) as is the shape of the flower.

So what baffles me is why all the reference books and on-line sites
(that I've found) say 20mm dia flowers?

Asha Santon

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Aug 13, 2015, 5:41:04 PM8/13/15

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That is Herb Robert. More deeply coloured than I am used to.

> So what baffles me is why all the reference books and on-line sites
> (that I've found) say 20mm dia flowers?

Because that is the size of the flowers on a fully developed plant
growing in its normal habitat.
I get some willowherb growing in cracks on the patio and if left to
flower, they are quite small. Your plant seems to have been trying to
grow on a length of pipe so is not getting full nutrition perhaps.

In the case of the Robert/Robin, the pollen and or the fruit (very
wrinkled in Robin) is indicative whereas the flower size is a guide.

--
A S
http://nature.opcop.org.uk

http://pictures.opcop.org.uk

Michael J Davis

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Aug 16, 2015, 6:06:48 AM8/16/15

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The ones in the area seem quite strongly coloured. Difficult with a
photo to determine the level of saturation (and on other people's
monitors!)

>> So what baffles me is why all the reference books and on-line sites
>> (that I've found) say 20mm dia flowers?
>
>Because that is the size of the flowers on a fully developed plant
>growing in its normal habitat.
>I get some willowherb growing in cracks on the patio and if left to
>flower, they are quite small. Your plant seems to have been trying to
>grow on a length of pipe so is not getting full nutrition perhaps.

Thanks - went to a wild place yesterday and found lots of examples -
some in very fertile areas - they were *all* in the 8-12mm diameter.
Conclude that the local variety is just smaller.

>In the case of the Robert/Robin, the pollen and or the fruit (very
>wrinkled in Robin) is indicative whereas the flower size is a guide.

Thanks again!