Poison hemlock (sick?)

Description:

These plants appear to have dying (or at least chlorophyll-deprived) limbs. In some plants, chlorophyll degradation occurs as a form of damage control in injured tissues (Kariola 2005).

Habitat:

Grassland/disturbed area with many bourgeoning poison hemlock plants, growing into shallow thickets.

Notes:

See previous spottings for more detailed photos of poison hemlock to confirm ID. I would have included them here but my focus was on the abnormal plants. Later: Having observed this in about a bajillion plants now, I'm thinking that it might just be a natural/normalish occurrence when the plant runs out of water in proportion to its growth rate. I don't know.