field note: Tanacetum annuum (blue tansy)

observation
the plant itself is not blue. fresh flowers are yellow, with finely divided green leaves. the blue color associated with blue tansy appears only after distillation.

transformation
during distillation, matricin is converted into chamazulene. this produces a deep indigo oil. the color is a result of heat-driven chemical change, not present in the living plant.

properties
blue tansy essential oil is strongly anti-inflammatory. it is often used to reduce redness, irritation, and reactive skin responses.

case note
client presented with solar urticaria. symptoms included swelling, redness, and burning upon sun exposure. condition had been ongoing for ~30 years.

a topical cream containing blue tansy essential oil was applied during an active reaction.

within ~15 minutes:

• visible reduction in redness

• decreased swelling

• reported reduction in pain

note
this was the first time i observed a meaningful interruption of that response in real time.