Dioscorea 1a San Diego de Los Baños, Cuba 190319 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 1 Lund Bot Garden 130816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 10 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 11 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 12 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 13 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 14 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 15 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 16 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 17 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 18 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 2 Lund Bot Garden 130816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 21 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 22 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 3 Lund Bot Garden 130816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 6 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 7 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 8 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 9 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea cf parviflora 1 Tiger Creek, Zapallar, Chile 171105 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea cf parviflora 2 Tiger Creek, Zapallar, Chile 171105 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 1 Holomondas, Greece 050528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 10 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 11 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 12 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 14 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 15 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 2 Holomondas, Greece 050528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 3 Holomondas, Greece 050528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 5 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 6 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 7 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 8 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 9 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea edulis 1 Barr. del Infierno, Tenerife 160406 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea edulis 2 Barr. del Infierno, Tenerife 160406 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea edulis 3 Barr. del Infierno, Tenerife 160406 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea edulis Barranco del Infierno, Tenerife 060415 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea elephantopus Copenhagen Bot Garden 120926 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea macroura 1 Lund Bot Garden 130816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 1 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 2 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 3 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 4 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 5 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea quinqueloba 5 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 1 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 2 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 3 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 4 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 5 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 6 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 7 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea saxatilis 8 Rio Clarillo Nat Park, Chile 171104 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 19 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 20 (cult) Stångby Sk 190607 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 4 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea caucasica 5 Copenhagen Bot Garden 150626 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 13 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea communis 4 Gibraltar, Great Britain 120321 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea macroura 2 Lund Bot Garden 130816 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea polystachya 6 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea quinqueloba 1 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea quinqueloba 2 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea quinqueloba 3 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Dioscorea quinqueloba 4 Copenhagen Bot Garden 130913 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).