Erysimum asperum

Wallflower Wall"flow`er, n. 1. (Bot.) A perennial, cruciferous plant ({Cheiranthus Cheiri}), with sweet-scented flowers varying in color from yellow to orange and deep red. In Europe it very common on old walls. [1913 Webster]

Note: The name is sometimes extended to other species of {Cheiranthus} and of the related genus {Erysimum}, especially the American {Western wallflower} ({Erysimum asperum}), a biennial herb with orange-yellow flowers. [1913 Webster]

2. A lady at a ball, who, either from choice, or because not asked to dance, remains a spectator. [Colloq.] [1913 Webster]

3. (Bot.) In Australia, the desert poison bush ({Gastrolobium grandiflorum}); -- called also {native wallflower}. [Webster 1913 Suppl.]