Family – Sunflower Asteraceae
Life Cycle – creeping perennial
Habitat – forage crops, hay fields, rangeland, roadsides, waste areas
- Short rhizomes
- Fern-like, aromatic leaves
- Yellow, button-like heads in clusters
The cotyledons and first true leaves are oval. The early leaves are petioled, hairy and have a slightly lobed margin. As leaves are produced, each one has progressively more lobes than the previous ones. Later, leaves tend to have a smooth surface.
Tansy has short rhizomes and tends to form large clumps of smooth, erect stems. The lower leaves are long-stalked and deeply cut into segments, which are, in turn, divided. They appear almost fern-like. Stem leaves are numerous, sessile and smaller than the basal leaves. Both types of leaves are covered with small glands and the entire plant is aromatic. Tansy is poisonous to livestock, but is usually avoided because of the strong odor.
Heads are in dense, round to flat-topped clusters. Each head is button-like and composed of many tightly packed, yellow disk flowers. The seeds are grey-tan, ribbed and lack an obvious pappus.