Acacia 1b Sabino Canyon, Tucson, Arizona 130424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 1c Sabino Canyon, Tucson, Arizona 130424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 1d Sabino Canyon, Tucson, Arizona 130424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 2a Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 2b Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 3a E of Walpole, Western Australia 110930 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 3b E of Walpole, Western Australia 110930 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 4a East Mount Barren, W of Hopetoun, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 4b East Mount Barren, W of Hopetoun, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 4c East Mount Barren, W of Hopetoun, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 4d East Mount Barren, W of Hopetoun, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 6d W of Pemberton, Western Australia 110928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 7a Western Flora, Western Australia 110925 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 8a W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 8b W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 8c W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 8d W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 9 Bontebok Nature Reserve, Western Cape, South Africa 011025 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia assimilis ssp assimilis 2 W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia bifaria 1 SE of Ravensthorpe, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia bifaria 2 SE of Ravensthorpe, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia bifaria 4 SE of Ravensthorpe, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf farnesiana 1 Santa Barbara Botanic Garden, CA 130411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf farnesiana 2 Santa Barbara Botanic Garden, CA 130411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf pentadenia 1 D'Entrecasteaux National Park, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf pentadenia 2 D'Entrecasteaux National Park, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf pentadenia 3 D'Entrecasteaux National Park, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf pentadenia 4 D'Entrecasteaux National Park, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 1 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 2 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 3 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 4 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 5 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 6 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 7 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia drummondii ssp elegans 8 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

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

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

Acacia farnesiana 3 Santa Barbara Botanic Garden, CA 130411 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia glaucoptera 1 Perth Bot Garden, Western Australia 111008 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia glaucoptera 2 Perth Bot Garden, Western Australia 111008 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia glaucoptera 3 Perth Bot Garden, Western Australia 111008 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 1 Iliau Loop Trail, Kauai, Hawaii 130713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 10 Kipuka Puaulu, Kilauea, Big Island, Hawaii 130724 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 2 Iliau Loop Trail, Kauai, Hawaii 130713 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 3 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 4 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 5 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 6 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 7 National Tropical Botanical Gardens, Kalehua, Kauaii, Hawaii 130711 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 9 Kipuka Puaulu, Kilauea, Big Island, Hawaii 130724 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 1 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 2 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 4 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 6 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia littorea 1 E of Walpole, Western Australia 110930 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia littorea 2 E of Walpole, Western Australia 110930 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia littorea 3 E of Walpole, Western Australia 110930 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia littorea 4 Mandalay Beach W of Walpole, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia littorea 5 Mandalay Beach W of Walpole, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia longifolia 1 Caledon Nature Reserve, Western Cape, South Africa 100920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia longifolia 2 Caledon Nature Reserve, Western Cape, South Africa 100920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia longifolia 3 Caledon Nature Reserve, Western Cape, South Africa 100920 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 1 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 2 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 4 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia poliochroa 1 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia poliochroa 5 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia redolens 1 Bergianska, Stockholm 131128 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia redolens 2 Bergianska, Stockholm 131128 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia saligna 3 Western Flora, Western Australia 110925 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 1 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 2 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 3 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 4 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia willardiana 1 Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia willardiana 2 Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia willardiana 3 Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia willardiana 4 Desert Botanical Garden, Phoenix, Arizona 130426 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 1a Sabino Canyon, Tucson, Arizona 130424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 1e Sabino Canyon, Tucson, Arizona 130424 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 5a Hassel National Park E of Albany, Western Australia 111002 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 5b Hassel National Park E of Albany, Western Australia 111002 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 5c Hassel National Park E of Albany, Western Australia 111002 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 6a W of Pemberton, Western Australia 110928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 6b W of Pemberton, Western Australia 110928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 6c W of Pemberton, Western Australia 110928 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia 7b Western Flora, Western Australia 110925 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia assimilis ssp assimilis 1 W of Hyden, Western Australia 111006 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia bifaria 3 SE of Ravensthorpe, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia cf pentadenia 5 D'Entrecasteaux National Park, Western Australia 110929 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia koa 8 Kipuka Puaulu, Kilauea, Big Island, Hawaii 130724 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 3 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia lasiocarpa 5 Bluff Knoll, Stirling Range, Western Australia 111001 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 3 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 5 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia mearnsii 6 Polipoli, Maui, Hawaii 130720 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia poliochroa 2 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia poliochroa 3 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia poliochroa 4 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia redolens 3 Bergianska, Stockholm 131128 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia saligna 1 Western Flora, Western Australia 110925 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia saligna 2 Western Flora, Western Australia 110925 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 5 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

Acacia uncinella 6 Lake King, Western Australia 111004 - Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).