What shrub's berries contain cyanogenic compounds if pits are crushed?

The shrub whose berries contain cyanogenic compounds when their pits are crushed is choke cherry, Prunus virginiana. The fruit’s juicy pulp can be used in traditional foods, jams, syrups, and wine, but the hard stone inside each berry must be treated with care.

The pits and other plant tissues contain cyanogenic glycosides, especially amygdalin and prunasin. When a pit is cracked, chewed, or ground, enzymes can break these compounds down and release hydrogen cyanide. Swallowing an intact pit is less likely to release the toxin because the hard shell may pass through the digestive tract undamaged, but crushed pits present a clear hazard.

Chokecherry is native to North America and was an important traditional food for many Indigenous peoples, including in pemmican and sun-baked fruit cakes. The ripe fruit is strongly astringent and becomes darker and somewhat sweeter as it matures. Livestock are also at risk from wilted chokecherry leaves, which can release cyanide and become deceptively palatable.