Achillea erba-rotta, common name simple leaved milfoil, is a perennial flowering plant of the genus Achillea, belonging to the sunflower family.[1]
Achillea erba-rotta is a polymorphic species, as its physical characteristics clearly vary depending on the variety. The biological form is chamaephyte suffruticose,[2] as these plants have perennating buds borne close to the ground and are woody in the lower part of the stem, with herbaceous yearly branches. The primary root is a rhizome.
This plant reaches on average 12- in height.[2] The stems are woody and creeping, almost glabrous or with short hair and with erect flowering branches. Leaves of sterile branches are lanceolate-spatulate, 5–7 mm wide and 26–30 mm long, with 4-7 teeth on each side.[2] Cauline leaves are alternate, sessile, toothed and progressively linear, about 2–3 mm wide and 11–22 mm long.[2] Flowers are hermaphroditic and pentamerous, arranged in corymbs with many heads, about 3 mm in diameter, with rounded ligules.[2] The flowering period extends from July through August. The fruit is a flattened achene without pappus.
This typical plant of Alps is present in Italy, France, Switzerland and Austria.[2] [3]
It prefers a sunny location in alpine pastures and rocky areas, at an altitude of 2000- above sea level.[2]