Bidens asymmetrica 4 Manoa Cliff Trail, Tantalus, Oahu, Hawaii 130709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens asymmetrica 5 Manoa Cliff Trail, Tantalus, Oahu, Hawaii 130709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Bidens aurea 3 Lund Botanical Garden 130825 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 6 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 7 Laesten, Jylland 950809 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens dahlioides 1 Lund Bot Garden 120720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens dahlioides 2 Lund Bot Garden 120720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens dahlioides 3 Lund Bot Garden 120720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens ferulifolia 3 Lund Bot Garden 130826 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 1 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 10 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 11 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 12 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 14 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 15 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 16 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 17 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 19 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 2 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 20 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 21 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 22 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 3 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 4 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 5 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 6 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 7 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 8 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 9 near Merkine, Lithuania 150806 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa Merkine, Lithuania 100714 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens mauiensis 1 Maui Nui Botanical Garden, Kaluhui, Maui, Hawaii 130718 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens mauiensis 2 Maui Nui Botanical Garden, Kaluhui, Maui, Hawaii 130718 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 1 Stångby, Skåne 050717 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 10 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 11 Lund Bot Garden 150818 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 12 Lund Bot Garden 150818 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 2 Stångby, Skåne 050717 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 3 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 4 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 5 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 6 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 7 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 8 Saxtorp Sk 141116 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 9 Saxtorp Sk 141116 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 10 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 11 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 3 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 4 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 5 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 6 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 8 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 9 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 1 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 11 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 12 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 2 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 3 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 4 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 5 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 6 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 7 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 8 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens sandvicensis ssp confusa 1 Iliau Loop Trail, Kauai, Hawaii 130713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens sandvicensis ssp confusa 2 Iliau Loop Trail, Kauai, Hawaii 130713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens torta 1 Puu Kaua, Oahu, Hawaii 840226 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens torta 3 Puu Kaua, Oahu, Hawaii 840226 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 2 Täby, Uppland 020731 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 3 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 4 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 5 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 6 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 7 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens triplinervia var macrantha 1 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens triplinervia var macrantha 2 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens triplinervia var macrantha 3 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens valida 4 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens asymmetrica 1 Manoa Cliff Trail, Tantalus, Oahu, Hawaii 130709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens asymmetrica 2 Manoa Cliff Trail, Tantalus, Oahu, Hawaii 130709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens asymmetrica 3 Manoa Cliff Trail, Tantalus, Oahu, Hawaii 130709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 1 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 2 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 3 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 4 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens cernua 5 Snårestad Sk 130907 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens ferulifolia 1 Lund Bot Garden 130826 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens ferulifolia 2 Lund Bot Garden 130826 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 13 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 18 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens frondosa 23 Kallinge, Blekinge 150920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 1 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens pilosa 2 Saxtorp Sk 141130 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 1 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 2 Valkiakoski between Tykölänjärvi and Mallasvesi N Hattula 120802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens radiata 7 Vuonoviken W of Haparanda, Norrbotten 220729 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 10 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens reptans 9 Cerro de la Muerte, Costa Rica 231211 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens sandvicensis ssp confusa 3 Iliau Loop Trail, Kauai, Hawaii 130713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens torta 2 Puu Kaua, Oahu, Hawaii 840226 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 1 Täby, Uppland 020731 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens tripartita 8 Vomb Sk 130928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens valida 1 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens valida 2 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Bidens valida 3 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).