Persicaria amphibia 1 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 2 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 6 Tvorup Klitplantage, Jylland DK 230802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria capitata Lund Bot Garden 120912 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 4 Blekinge, Mörrumsåns utlopp 110814 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 5 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 6 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp pallida 1 Skanör Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp pallida 2 Skanör Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp pallida 3 Skanör Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp pallida var incana Edsberg, Sollentuna 980723 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 1 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 2 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 3 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 4 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 5 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 6 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 7 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 13 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 14 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria strindbergii Shika, Yunnan 110712 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Persicaria tenuicaulis 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria tenuicaulis 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria umbrosa Dali, Yunnan 110706 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 3 Rammsjöstrand, Västra Karup Sk 130624 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 4 Rammsjöstrand, Västra Karup Sk 130624 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 5 Rammsjöstrand, Västra Karup Sk 130624 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria amphibia 7 Tvorup Klitplantage, Jylland DK 230802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 1 Blekinge, Mörrumsåns utlopp 110814 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 2 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria hydropiper 3 Källby, Lund Sk 130812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp lapathifolia Mörby, Danderyd, Uppland 980805 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria lapathifolia ssp pallida 4 Skanör Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria maculosa 1 Lund Bot Garden 130825 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria maculosa 2 Lund Bot Garden 130825 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria maculosa 3 Lund Bot Garden 130825 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria maculosa 4 Lund Bot Garden 130825 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 10 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 11 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 8 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria minus 9 Stehag Sk 140816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 1 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 10 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 11 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 12 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 2 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 3 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 4 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 5 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 6 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 7 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 8 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria mitis 9 Bukta forest SE of Zelsva S of Marijampole, Lithuania 150807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria tenuicaulis 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria tenuicaulis 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria virginiana 1 Copenhagen Bot Garden 120926 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Persicaria virginiana 2 Copenhagen Bot Garden 120926 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).