Achillea millefolium
Achillea millefolium (a dicot also known as "common yarrow") can be easily identified by its fragrant and seemingly daisy-like flowers which blossom with a creamy white color but slowly age to faint pink by the end of the season. The species name, millefolium, means 'of a thousand leaves,' and describes the feathery foliage, which resembles a fern. The yarrow's leaves are also grayish-green and are formed from rhizomes found beneath the soil's surface.
The common yarrow can be found throughout the temperate regions of North America but are originally native to Europe and western Asia. In the United States, the yarrow is commonly used alongside highways, in wildflower gardens. It is also commonly found in fields and meadows. In Utah, the yarrow is found at elevations from 1,270 to 3,550 meters.
Sometimes regarded as a weed, the yarrow is a drought tolerant perennial. Little care is required to make this plant grow, but it does require full sunlight. Fertilizer should not be used, as the yarrow grows best on poor soils that are well-drained. Temperature is also an important factor, as the yarrow survives best with temperatures below 80¡F. The yarrow's foliage is resistant to insects and disease but may suffer from mildew or rust. The yarrow can be very invasive and should not be planted near less aggressive plants.
The common yarrow has a sister species named Achillea millefolium lanulosa (or mountain yarrow), which is found in several woodland and mountain communities and is native to California (pictured middle left).
Common yarrow has been used as a salad green, beer additive, snuff, poultice, wound dressing, astringent, antidepressant, stimulant, antispasmodic, fever reducer, blood pressure reducer, and perspiration inducer for many centuries. Carolus Linnaeus, the father of botanical nomenclature, coined the generic name Achillea, in honor of Achilles, the Greek hero of the Trojan War, who used yarrow to treat his soldiers' war wounds. The yarrow actually may be useful in treating circulatory problems, fever, colds, flu, high blood pressure and hay fever, but, despite its long history of use, there has been surprisingly little research into its usefulness and safety. In the United States, use of the yarrow in commercial products is only allowed as a flavoring in beverages by the FDA. Animals usually do not eat yarrow, but when they do, they only eat the flowers. Also, cows that eat yarrow produce bitter milk.
The common yarrow must be used carefully, as allergies have been induced by the foliage and/or sap of the yarrow. Also, prolonged use has been known to increase the skin's sensitivity towards sunlight. Nevertheless, the yarrow provides a drought-tolerant addition to the Utah garden, and the variety in flower color makes this addition pleasing to the eyes.
