Erythronium 1b Lilla Frescati, Stockholm 020508 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium americanum 1 Lilla Frescati, Stockholm 060505 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium americanum 3 Storrs, Connecticut 900428 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium americanum 4 Storrs, Connecticut 900428 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 5 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 6 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 5 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 6 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium 1a Lilla Frescati, Stockholm 020508 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium americanum 2 Lilla Frescati, Stockholm 060505 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium americanum 5 Storrs, Connecticut 900428 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 1 Lund Bot Garden 140331 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 2 Lund Bot Garden 140331 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 3 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 4 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 7 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 8 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium dens-canis 9 Belagua valley, Navarra, Spain 180525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Erythronium oregonum sulphur form Göteborg Bot Garden 130524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 1 Copenhagen Bot Garden 100421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 2 Copenhagen Bot Garden 100421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 3 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Erythronium tuolumnense 4 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).