Staggerweed

Staggerweed or stagger weed, a plant so named because it produces staggers in livestock that graze it, usually refers to Stachys arvensis.

It can also refer to other plants including:
 * Consolida regalis syn. Delphinium consolida
 * Corydalis cava
 * Delphinium spp.
 * Delphinium tricorne
 * Dicentra eximia syn. Fumaria eximia
 * Dicentra canadensis
 * Dicentra cucullaria
 * Helenium autumnale
 * Jacobaea vulgaris syn. Senecio jacobaea, also called staggerwort