Erysimum 3c between Topolovgrad and Hljabovo, Bu 120507 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 4b NE Spili, Crete 110327 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 4c NE Spili, Crete 110327 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 5c Dolna Kula, Bu 120509 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 6c Vashlovani Nat. Park, Georgia 170424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum asperum 3 Copenhagen Bot Garden 080710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum bicolor 3 Barranco del Infierno, Tenerife 060415 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf crassistylum 2 near Lake Mikri Prespa, N Greece 180629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf crassistylum 3 near Lake Mikri Prespa, N Greece 180629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf crassistylum 4 near Lake Mikri Prespa, N Greece 180629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf diffusum 1 Daugavpils stn, Latvia 100712 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf scoparium 3 Cruz de Tejeda, Gran Canaria 080414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 5 Lohja FI 120803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 6 Lohja FI 120803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 7 Edsberg, Sollentuna, Uppland 060928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiri 3 Bergianska, Stockholm 131128 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum horizontale 3 Lesbos OSO Filia 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

Erysimum humile 5 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 4 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 5 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum linifolium 1 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum linifolium 2 Copenhagen Bot Garden 080710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum marschallianum 1 Tallinn, Estonia 100708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum marschallianum 2 Tallinn, Estonia 100708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mutabile Omalos, Crete 8005 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum odoratum 1 Turda, Romania 090614 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum odoratum 2 Turda, Romania 090614 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pieninicum 4 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pulchellum 2 Göteborg Bot Garden 130524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pulchellum 3 Göteborg Bot Garden 130524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 4 Lund Bot Garden 150713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 5 Lund Bot Garden 150713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum strictum 1 Kallviksudden (Kallavi) FI 120728 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum strictum 2 Kallviksudden (Kallavi) FI 120728 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum witmannii 4 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum witmannii 5 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 1 W of Zilina, Czekia 950630 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 2 3 km SW of Polygyros, Greece 050526 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 3a between Topolovgrad and Hljabovo, Bu 120507 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 3b between Topolovgrad and Hljabovo, Bu 120507 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 4a NE Spili, Crete 110327 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 5a Dolna Kula, Bu 120509 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 5b Dolna Kula, Bu 120509 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 5d Dolna Kula, Bu 120509 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 6a Vashlovani Nat. Park, Georgia 170424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum 6b Vashlovani Nat. Park, Georgia 170424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum asperum 1 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum asperum 2 Copenhagen Bot Garden 080710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum bicolor 1 Barranco de Las Cuevas Negras, Tenerife 970321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum bicolor 2 Barranco de Las Cuevas Negras, Tenerife 970321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum capitatum 1 Gorman Hills, CA 130409 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum capitatum 2 Gorman Hills, CA 130409 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf crassistylum 1 near Lake Mikri Prespa, N Greece 180629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf crassistylum 5 near Lake Mikri Prespa, N Greece 180629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf diffusum 2 Daugavpils stn, Latvia 100712 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf scoparium 1 Cruz de Tejeda, Gran Canaria 080414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cf scoparium 2 Cruz de Tejeda, Gran Canaria 080414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp altum 1 Sveaborg FI 120804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp altum 2 Sveaborg FI 120804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp altum 3 Sveaborg FI 120804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 1 Höllviken Sk 130608 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 2 Höllviken Sk 130608 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 3 Lohja FI 120803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiranthoides ssp cheiranthoides 4 Lohja FI 120803 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiri 1 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum cheiri 2 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum diffusum 1 NW of Straznice, Czekia 950701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum diffusum 2 NW of Straznice, Czekia 950701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum diffusum 3 NW of Straznice, Czekia 950701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum durum 1 Peberholm, DK 090804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum durum 2 Peberholm, DK 090804 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum horizontale 1 S of Lastos, Karpathos, Greece 040519 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum horizontale 2 Lesbos OSO Filia 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum humile 2 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 1 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 2 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 3 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 6 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum jugicola 7 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum linifolium 2 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum marschallianum 3 Tallinn, Estonia 100708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum 1 Sierra de Mijas, Andalucía Spain 220414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum 2 Sierra de Mijas, Andalucía Spain 220414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum 3 Sierra de Mijas, Andalucía Spain 220414 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum ssp rondae 1 Sierra de Alcaparaín, Andalucía Spain 220411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum ssp rondae 2 Sierra de Alcaparaín, Andalucía Spain 220411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum ssp rondae 3 Sierra de Alcaparaín, Andalucía Spain 220411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum mediohispanicum ssp rondae 4 Sierra de Alcaparaín, Andalucía Spain 220411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum odoratum 3 Suatu, Romania 090613 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pieninicum 1 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pieninicum 2 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pieninicum 3 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pieninicum 5 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum pulchellum 1 Göteborg Bot Garden 130524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 1 Lund Bot Garden 150713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 2 Lund Bot Garden 150713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 3 Lund Bot Garden 150713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum rhaeticum 6 Lund Bot Garden 150717 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum sylvestre 1 Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum sylvestre 2 Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum wahlenbergii 1 Tatranská Kotlina, Slovakia 950627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum wahlenbergii 2 Tatranská Kotlina, Slovakia 950627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum witmannii 1 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum witmannii 2 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erysimum witmannii 3 Copenhagen Bot Garden 130611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).