Photo of a Black on Black plant species, one of several rare or botanically interesting plant species that cover about seven of the 17-acre Carls S. English Jr. Botanical Garden, Lake Washington Ship Canal and Hiram M. Chittenden Locks, Seattle, Washington. The ArbNet Arboretum Accreditation Program and The Morton Arboretum awarded this accreditation to the botanical garden, for achieving particular standards of professional practices deemed important for arboreta and botanic gardens.