Cenchrus agrimonioides 5 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 10 Lund Bot Garden 120908 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 4 Lund Bot Garden 110901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 5 Lund Bot Garden 110901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 9 Lund Bot Garden 120908 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus 2 (cult) Dubai, United Arab Emirates 161030 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus 3 (cult) Dubai, United Arab Emirates 161030 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus 4 (cult) Dubai, United Arab Emirates 161030 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus 5 (cult) Dubai, United Arab Emirates 161030 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus agrimonioides 1 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus agrimonioides 2 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus agrimonioides 3 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus agrimonioides 4 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus agrimonioides 6 Lyon Arboretum, Honolulu, Hawaii 130708 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 1 Lund Bot Garden 110901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 2 Lund Bot Garden 110901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 3 Lund Bot Garden 110901 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 6 Lund Bot Garden 120908 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 7 Lund Bot Garden 120908 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus alopecuroides 8 Lund Bot Garden 120908 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus barbatus 1 Copenhagen Bot Garden 121017 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus barbatus 2 Copenhagen Bot Garden 121017 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus barbatus 3 Copenhagen Bot Garden 121017 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus ciliaris 1 Masafi Wadi, United Arab Emirates 161101 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus ciliaris 2 Masafi Wadi, United Arab Emirates 161101 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 1 Barranco Angustias, La Palma 090502 - Photo: Richard Åkesson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 2 (cult) Visby, Gotland 140829 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 3 (cult) Visby, Gotland 140829 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 4 (cult) Visby, Gotland 140829 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 5 (cult) Visby, Gotland 140829 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus setaceus 6 (cult) Visby, Gotland 140829 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus (cult) Stångby, Skåne 040802 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Cenchrus villosus 1 (cult) Dubai, United Arab Emirates 161030 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).