Marrubium incanum 3 Copenhagen Bot Garden 150812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium incanum 4 Copenhagen Bot Garden 150812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Marrubium peregrinum 6 Lake Kerkini, N Greece 180702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium peregrinum 7 Lake Kerkini, N Greece 180702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium peregrinum 8 Lake Kerkini, N Greece 180702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium peregrinum 9 Lake Kerkini, N Greece 180702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 10 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 3 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 4 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 5 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 6 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 9 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium velutinum 1 the Katara Pass, N Greece 180627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium velutinum 2 the Katara Pass, N Greece 180627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium velutinum 3 the Katara Pass, N Greece 180627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 1 Lilla Karlsö, Gotland 910726 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 10 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 11 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 12 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 13 (cult) Kulturen, Lund Sk 190810 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 14 (cult) Kulturen, Lund Sk 190810 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 15 (cult) Kulturen, Lund Sk 190810 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 16 (cult) Kulturen, Lund Sk 190810 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 17 (cult) Kulturen, Lund Sk 190810 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 2 Lilla Karlsö, Gotland 910726 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 4 Sandvik, Persnäs, Öland 790813 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 9 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium incanum 1 Copenhagen Bot Garden 150812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium incanum 2 Copenhagen Bot Garden 150812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Marrubium peregrinum 5 Lake Kerkini, N Greece 180702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 1 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium supinum 2 Lund Bot Garden 160605 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium velutinum 4 the Katara Pass, N Greece 180627 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 3 Sandvik, Persnäs, Öland 790813 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 5 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 6 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 7 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Marrubium vulgare 8 near Potochnitsa, Bulgaria 120510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).