Rhododendron 10a Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 10b Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 10c Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 10d Copenhagen Botanical Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 11b Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 12a Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 12b Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 12c Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 13a (cult) Brunnby Sk 150618 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 13b (cult) Brunnby Sk 150618 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

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

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

Rhododendron 2a (orig Yunnan) Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 2b (orig Yunnan) Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 2c (orig Yunnan) Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

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

Rhododendron 5a Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 5b Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 5c Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 6a Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 6b Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 6c Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 7a Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 8a Napa Hai, Yunnan 110709 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron 8b Napa Hai, Yunnan 110709 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron 8c Napa Hai, Yunnan 110709 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron 8d Napa Hai, Yunnan 110709 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron 9a Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 9b Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 9c Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 9d Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 9e Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron aberrans 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron aganniphum var aganniphum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron aganniphum var aganniphum 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron aganniphum var aganniphum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron albrechtii 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron ambiguum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ambiguum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron bureavii 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron calendulaceum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron calendulaceum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calendulaceum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calostrotum ssp keleticum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calostrotum ssp keleticum 2 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calostrotum ssp keleticum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calostrotum ssp keleticum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron campanulatum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron campanulatum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron campanulatum 6 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron campylogonum 1 near Lijiang, Yunnan 110707 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron campylogonum 2 near Lijiang, Yunnan 110707 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron campylogonum 3 near Lijiang, Yunnan 110707 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron camtschaticum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron camtschaticum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron camtschaticum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron canadense 1 N of Storrs, Connecticut 900519 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron canadense 2 N of Storrs, Connecticut 900519 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cephalanthum Yunnan 1107 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cf wardii 1 (cult) Brunnby Sk 120619 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cf wardii 2 (cult) Brunnby Sk 120619 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron cinnabarinum ssp cinnabarinum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cinnabarinum ssp xanthocodum 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cinnabarinum ssp xanthocodum 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cinnabarinum ssp xanthocodum 3 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron complexum 2 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron complexum 3 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron complexum 4 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron complexum 5 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron concinnum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron concinnum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron concinnum 6 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron cruentum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron cuneatum 1 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron cuneatum 2 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron dauricum Bergianska, Stockholm 050513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron decorum 1 Kunming Bot Garden 110705 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron decorum 2 Kunming Bot Garden 110705 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron degronianum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron degronianum ssp degronianum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp degronianum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp degronianum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp yakushimanum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp yakushimanum 2 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp yakushimanum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp yakushimanum 4 Lund Bot Garden 130527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron degronianum ssp yakushimanum 5 Lund Bot Garden 130527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron dichroanthum 1 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron dichroanthum 2 Copenhagen Bot Garden 140424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 1 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 10 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 11 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 12 Col d'Izoard FR 150709 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 2 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 3 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 4 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 5 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 6 Stubnerkogel, Austria 080702 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 7 Copenhagen Bot Garden 120919 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 8 Copenhagen Bot Garden 120919 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ferrugineum 9 Copenhagen Bot Garden 120919 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron fortunei 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron fortunei 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron fortunei 3 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron fortunei 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron fortunei 6 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron galactinum 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron galactinum 6 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron galactinum 7 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron galactinum 8 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron glandulosum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron glandulosum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron glaucophyllum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron glaucophyllum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron glaucophyllum 8 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron glaucophyllum 9 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 1 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 3 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 4 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 5 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 6 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 8 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 9 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp chaetomallum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp chaetomallum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp chaetomallum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp chaetomallum 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp chaetomallum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp haematodes 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp haematodes 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp haematodes 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp haematodes 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron haematodes ssp haematodes 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron heliolepis 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron hirsutum 2 Copenhagen Bot Garden 140625 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron hunnewellianum Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron impeditum 2 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron impeditum 3 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron johnstoneanum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

Rhododendron keiskei 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron lapponicum 1 Store Saltsö, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lapponicum 2 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lapponicum 3 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lapponicum 5 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lapponicum 6 Unna Titer, Lule Lappmark 870714 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lepidotum 1 near Lijiang, Yunnan 110707 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron lepidotum 2 near Lijiang, Yunnan 110707 - Photo: Magnus Thorell (© 2014 Jan Thomas Johansson).

Rhododendron lepidotum 3 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lepidotum 4 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lepidotum 5 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lochiae 1 Lyon Arboretum, Honolulu, Hawaii (orig northestern Queensland) 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lochiae 2 Lyon Arboretum, Honolulu, Hawaii (orig northestern Queensland) 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 1 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 2 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 3 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 4 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 5 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 6 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 7 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 8 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron luteum 9 SSE Pteroundas, Lesvos, Greece 100510 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron macgregoriae Mt Kaindi, Papua New Guinea 831028 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron makinoi 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron makinoi 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron molle ssp japonicum 1 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron molle ssp japonicum 2 Bergianska 150527 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron molle ssp japonicum 6 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron molle ssp japonicum 7 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronatum 1 Copenhagen Bot Garden 140312 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronatum 3 Copenhagen Bot Garden 140312 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronatum 4 Copenhagen Bot Garden 140312 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron mucronulatum 10 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronulatum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron mucronulatum 5 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronulatum 6 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronulatum 7 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronulatum 8 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronulatum 9 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron myrtifolium 1 Rodnea, Romania 090612 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron myrtifolium 3 Rodnea, Romania 090612 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron myrtifolium 4 Rodnea, Romania 090612 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron nakaharae 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron nakaharae 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron nudiflorum 1 Storrs, Connecticut 900528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron nudiflorum 2 Storrs, Connecticut 900519 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron obtusum 1 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron obtusum 2 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron obtusum 3 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron occidentale 1 Santa Barbara Botanic Garden, CA 130411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron occidentale 2 Santa Barbara Botanic Garden, CA 130411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron occidentale 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron occidentale 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron occidentale 6 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron oreotrephes 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron oreotrephes 6 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron pachysanthum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron pachysanthum 4 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron phaeochrysum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron planetum 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron planetum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron planetum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron ponticum 1 (cult) Brunnby Sk 170611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron ponticum 2 (cult) Brunnby Sk 170611 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron praecox 1 (cult) Brunnby Sk 150410 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron praecox 3 (cult) Brunnby Sk 150410 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron praecox 4 (cult) Brunnby Sk 150410 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron praecox 5 (cult) Brunnby Sk 150410 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron prinophyllum 1 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron prinophyllum 2 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron prinophyllum 3 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron prinophyllum 4 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron prinophyllum 5 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron rex ssp fictolacteum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rex ssp fictolacteum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rex ssp fictolacteum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron roxieanum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron rubiginosum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron rubiginosum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rubiginosum 6 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rubiginosum 7 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rukizon 1 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron rukizon 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rupicolum var chryseum 1 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rupicolum var chryseum 2 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rupicolum var chryseum 3 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rupicolum var chryseum 5 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 6 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 7 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron succothii 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron succothii 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron succothii 3 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron succothii 4 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 1 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 2 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 3 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 6 Mt Hassel, Kangerlussuaq, Greenland 140630 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 1 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 5 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 8 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron traillianum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron trichostomum 1 near Lijiang, Yunnan 110707 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron trichostomum 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron trichostomum 6 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron trichostomum 7 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron trichostomum 8 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron vaseyi 4 Göteborg Bot Garden 130524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

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

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

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

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

Rhododendron wardii 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron wardii 6 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron wardii 7 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron watsonii var rhododactylum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron watsonii var rhododactylum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron watsonii var rhododactylum 3 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron weyrichii Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron yunnanense 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron yunnanense 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 11a Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron 7b Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron aganniphum var aganniphum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron aganniphum var aganniphum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron albrechtii 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

Rhododendron bureavioides 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron calostrotum ssp keleticum 5 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron ciliatum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron cinnabarinum ssp cinnabarinum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron complexum 1 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron galactinum 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron galactinum 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron glandulosum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron glaucophyllum 6 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron glaucophyllum 7 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 2 Lake Ferguson, Kangerlussuaq, Greenland 140701 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron groenlandicum 7 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron heliolepis 1 Yunnan 1107 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron heliolepis 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron hirsutum 1 Copenhagen Bot Garden 140625 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron impeditum 1 Copenhagen Bot Garden 080513 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lapponicum 4 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lochiae 3 Lyon Arboretum, Honolulu, Hawaii (orig northestern Queensland) 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lochiae 4 Lyon Arboretum, Honolulu, Hawaii (orig northestern Queensland) 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron lochiae 5 Lyon Arboretum, Honolulu, Hawaii (orig northestern Queensland) 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronatum 2 Copenhagen Bot Garden 140312 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron mucronatum 5 Copenhagen Bot Garden 140312 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron myrtifolium 2 Rodnea, Romania 090612 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron nakaharae 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron oreotrephes 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron pachysanthum 3 Copenhagen Bot Garden 150421 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron praecox 2 (cult) Brunnby Sk 150410 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron rukizon 4 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron rupicolum var chryseum 4 Baimashan, Yunnan 110710 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 1 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron sikangense var exquisitum 5 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron smirnowii 1 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron smirnowii 2 (cult) Sofiero Sk 070521 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron temenium 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Rhododendron temenium 5 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 4 Tacan, Kangerlussuaq, Greenland 140629 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp decumbens 5 Mt Hassel, Kangerlussuaq, Greenland 140630 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 2 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 3 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 4 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 6 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 7 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron tomentosum ssp tomentosum 9 SW of Böda, Böda, Öland 220606 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron trichostomum 3 Copenhagen Bot Garden 130604 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Rhododendron viscosum 3 Göteborg Bot Garden 120628 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron wardii 2 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Rhododendron watsonii var rhododactylum 4 Copenhagen Bot Garden 130516 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).