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

Nigella arvensis 3 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 4 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 7 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella cf doerfleri W of Sitía, Crete 800518 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 3 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 7 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 8 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Nigella hispanica 3 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella hispanica 4 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella hispanica 5 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella hispanica 6 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella integrifolia Lund Bot Garden 9106 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Nigella nigellastrum 3 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella nigellastrum 4 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella nigellastrum 5 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella nigellastrum 6 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella nigellastrum 7 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella nigellastrum 8 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella orientalis 1 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella orientalis 2 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella orientalis 3 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella orientalis 4 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella orientalis 5 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella 1 Amopi, Karpathos, Greece 040523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 1 Lund Bot Garden 9106 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 5 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 6 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella arvensis 8 Panaghia, Greece 050525 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 1 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 2 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 4 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 5 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella ciliaris 6 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella damascena 3 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella damascena 4 Copenhagen Bot Garden 130821 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella hispanica 1 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella hispanica 2 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Nigella unguicularis 1 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 2 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 3 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 4 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 5 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 6 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Nigella unguicularis 7 Copenhagen Bot Garden 140719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).