Rhodiola dumulosa 1 Copenhagen Bot Garden 130625 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola dumulosa 2 Copenhagen Bot Garden 130625 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 2 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 3 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 4 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 5 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 6 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 7 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola heterodonta 8 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola kirilowii var rubra 1 Bergianska, Stockholm 050531 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola kirilowii var rubra 2 Bergianska, Stockholm 050531 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola pachyclados 10 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola pachyclados 11 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola pachyclados 13 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola pachyclados 9 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 1 Lund Bot Garden 130528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 10 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 11 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 12 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 14 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 3 Ansätten, Jämtland 090704 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 4 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 5 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 6 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 9 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

Rhodiola yunnanensis 3 Dali, Yunnan 110706 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola 1 NW of Shangri-la, Yunnan 110708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

Rhodiola heterodonta 1 Copenhagen Bot Garden 140515 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola pachyclados 12 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 13 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 2 Lund Bot Garden 130528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 7 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola rosea 8 Aran Islands, Clare, Ireland 170527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola semenovii 1 Bot Garden, Tromsø, Norway 220719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola semenovii 2 Bot Garden, Tromsø, Norway 220719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola semenovii 3 Bot Garden, Tromsø, Norway 220719 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola yunnanensis 1 Dali, Yunnan 110706 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhodiola yunnanensis 2 Dali, Yunnan 110706 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).