Jepson (2012) (APG System)

Order

Asterales

Family

Asteraceae

Jepson (1993) (Cronquist System)

Order

Asterales

Family

Asteraceae

Plant Relationships

California Species:

Achillea millefolium

Yarrow

Other Species:

Achillea clavennae
Achillea filipendulina
Achillea tomentosa

Silvery yarrow
Fernleaf yarrow
Wooly yarrow

Description

Growth Forms:

Herbaceous perennials.

Branching:

Alternate.

Leaves:

Pinnately dissected leaves, often with a feathery appearance. Yarrow leaves are usually aromatic, with a fragrance similar to sagebrush.

Flowers:

Achillea tends to flower in late spring or early summer. Most are white. There is a pink flowering form from the Channel Islands. There are also some yellow flowering species from other countries.

Seed and Fruit:

The abundant, small seeds ripen in mid to late summer. They stay in the flower head until it is shaken or moved sufficiently to make them fall out.

Growing Conditions

Sun and Exposure:

Achillea grows in full sun.

Soil and Moisture Requirements:

Achillea is found in a wide variety of soil and moisture conditions. It is usually found in well developed grassland soils where there is enough moisture to support perennials. It can be found, however, in drier sites, although it will go dormant early in these locations.

Natural Habitat and Range:

Achillea millefolium is a circumpolar species that is found in California, across Canada a down the Rockies and eastern seaboard, as well as Asia and europe.

Horticulture and Restoration

Horticultural Comments:

Yarrow is a very reliable and vigorous plant. It grows best is full sun. It does not require irrigation, but benefits from it. It is a standard "go-to" plant in landscaping.
 

Wildlife Habitat:

The flowers are widely visited by pollinators. The fragrance of the foliage is likely to repel herbivores. We never notice any grazing on Achillea.

Restoration Projects:

Achillea is often used in oak woodland and coastal projects, as well as small native grassland restorations.