Ceanothus leucodermis, chaparral whitethorn, a shrub in the family Rhamnaceae.
Bursaria spinosa, a small Australian shrub.
Crataegus monogyna, a hawthorn species native to Europe, northwest Africa and western Asia.
Vachellia constricta, formerly Acacia constricta, whitethorn acacia, a shrub in the family Fabaceae.