Corylus americana 1 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus americana 2 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus americana 3 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus americana Storrs, Connecticut 900528 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 1 Lund Sk 080523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 10 Höllviken Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 11 Höllviken Sk 120812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 12 Höllviken Sk 120812 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 2 Höllviken Sk 070401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 3 Höllviken Sk 130309 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 7 Höllviken Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 8 Höllviken Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

Corylus cornuta 1 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus cornuta 2 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus cornuta 3 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 1 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 2 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 5 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 6 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 7 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 8 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 9 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 2 Lund Bot Garden 090320 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 3 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 4 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 5 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 6 Lund Bot Garden 140524 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 4 Höllviken Sk 130309 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 5 Höllviken Sk 130309 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 6 Höllviken Sk 130309 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus avellana 9 Höllviken Sk 130901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

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

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

Corylus colurna 1 Lund Bot Garden 080205 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus colurna 2 Lund Bot Garden 080205 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus colurna 3 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus colurna 4 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus colurna 5 Lund Bot Garden 140523 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 3 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus heterophylla 4 Lund Bot Garden 130401 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Corylus sieboldiana 1 Lund Bot Garden 090320 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).