Callitriche brutia 1 SSE of Mandamados, Lesvos, Greece 100514 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche brutia 2 Vaernengene, Tipperne, Ringköbing Fjord, Jylland DK 130629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche brutia 3 Vaernengene, Tipperne, Ringköbing Fjord, Jylland DK 130629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 1 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 2 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 3 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 4 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 5 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 6 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 7 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata Skanörs Ljung, Skåne 940904 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hermaphroditica 1 Havgårdssjön, Börringe Sk 060809 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hermaphroditica 2 Havgårdssjön, Börringe Sk 060809 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hermaphroditica 3 Havgårdssjön, Börringe Sk 060809 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hermaphroditica 4 Havgårdssjön, Börringe Sk 060809 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche muelleri 1 Waipoua Forest, Northland NZ 151105 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche muelleri 2 Waipoua Forest, Northland NZ 151105 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 1 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 10 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 11 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 12 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 13 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 2 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 3 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 4 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 5 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 6 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 9 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche palustris 2 Törnskogen, Sollentuna, Uppland 040812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche palustris 3 Törnskogen, Sollentuna, Uppland 040812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche platycarpa 1 Ängelsbäcksstrand, Grevie Sk 170807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche platycarpa 2 Ängelsbäcksstrand, Grevie Sk 170807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche stagnalis 1 Ölberg S of Stavanger, Norway 050805 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 1 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 10 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 2 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 3 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 4 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 5 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 6 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 7 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 9 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 8 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche hamulata 9 S of Skjern, Jylland DK 140801 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche muelleri 3 Waipoua Forest, Northland NZ 151105 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 7 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche obtusangula 8 NW of Varming, Jylland DK 140803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche palustris 1 Bud, Norway 820805 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche palustris 4 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche palustris 5 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche platycarpa 3 Ängelsbäcksstrand, Grevie Sk 170807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche platycarpa 4 Ängelsbäcksstrand, Grevie Sk 170807 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche stagnalis 2 Ölberg S of Stavanger, Norway 050805 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Callitriche truncata 8 Skjern Enge, Jylland DK 230804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).