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I would expect the flower to be all one colour for subsp. nigra, whereas subsp. segetalis is two-toned as here.
But the leaves are different and much thinner in ssp nigra as seen here.
Wild Flower Society member
I find the leaves of segetalis vary quite a lot. Other characters are more useful.
Thanks but sticking by my id,
Go back when seed pods ripe - their differences should decide the issue.
Lat/Lng: 52.6434, 1.3134
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